This is clearly a case of "never a lender or borrower be".
There are two schools of thought about insurance, and it seems insurance companies will used the one that benefits them directly so they aren't out any money.
1 is the insurance follows the vehicle, and 2, the insurance follows the driver.
Heres two personal examples i know of:
1) long ago when i was young and foolish, i had a roommate who got a DUI. His license was suspended, but ge had to get to work and mandatory AA meetings. I drove him around to all he needed to do. But, one day i saud lets use your vehicle and your gas and mileage. Big mistake. As Snoopy would type "it was a dark and stormy night...". It was. And i drove him somewhere. Well tge storm had broken a branch on a roadside tree. I didnt see it hanging there until 2 feet from it hitting the windshield. He didnt see it either. It broke tge windshield and it had to be replaced. $150. We turned it into his insurance and got it replaced. Hus insurance went after my insurance to get reimbursed. My rates went up $400/yr for 4 years. As an aside i told my insurance company we turned it into his, he had, just couldn't drive it with a suspended license. I was yold tten that the insurance follows the driver, so therefore hus company subrogated mine. I was puseed and learned then that: a) i would not drive another person's vehicle unless insued on it and b) i would never let anyone drive my vehicle unless insured on it.
2) when my now spouse and i got together, i strongly suggested and we did each other to the policies we each had to avoid this problem. When we got married it was no problem, and it didn't cost us extra to be listed on the policies. We eventually realized it was stupid to have 2 companies and two policies, so we combined to one policy. Well fast forward to 3 years ago, my spouse was driving my vehicle as i had just had my neck fused two days before we went out, spouse driving my vehicle and we got rearended at a stop sign we were stopped at by a woman who hit us hard going 40 mph. My shpulder got jarred into the side window, and the whole back end of my vehicle had to be rebuilt. She panicked not wanting us to turn it in because it was her mother's vehicle, she wasnt insured on it, and her mother didn't know she had taken the vehicle!!. We said "not our problem lady", and called 911. I had to go to the the hospital to have my neck checked out as i just had surgery 2 days before to fuse my neck, and have physical therapy for the shoulder injury. When we went to our agent to do the paperwork, the first thing the other vehicles insurance said was " were not paying youll have to go after the drivers insurance " ( my spouse kept name not changing to mine so it was obvious the driver and vehicle owners names did not match). My agent said " but (spouse) is ON tge policy. As the cop said in a rearending situation the driver who hits from behind is always at fault., but NY is a nofault state. It ended up the insurance on the other vehicle had to pay to repair my vehicle, but my insurance had to pay my medical. The other vehicles insurance THOUGHT they could get away with not paying as they THOUGHT my spouse was separate insurance, in which case the insurance would have followed my spouse. Since my spouse was on the same policy, the otger vehicles insurance had to sing a different tune and pay up.
3) my parents neighbor had an adult daughter a year youbger than i. After high school and college she moved 5 states away. She came home and her old friends wanted to go out. Her parents lent her their car, as she didn't have a rental. She was backing out of her parent's driveway and hit a motorcycle that came out of nowhere. Bike driver seriously injured, and his bike was totaled, abd the car damaged. The daughters insurance would not cover her out of state. The parent's insurance tried to say The insurance should follow the daughter/driver. Long story short, the bike and his insurance sued and the parents lost EVERYTHING. they lost their bank accounts and retirement and the house with pool. They were alliwed to keep $1500 in furniture and clothing and one months of his pension and SS. EVERYTHING ELSE Was seized and sold off. The bikes insurance said the insurance follows the parents car, and since the award was higher than coverage the parents had, they lost everything.
Lessons learned: never drive a vehicle you aren't insured on, never let anyone else drive your vehicle if not insured on it, and carry HIGH liability coverage AND get a liability umbrella policy, which will cover you for/above homeowners and vehicles insurance. The umbrella will cover other sorts of liability too, but primarily covers what the regular policies wont cover.
OP, to echo others, you ARE screwed, as they will go after any money or assets you may have and go for judgment to garnish any of your pay for whatever they can get and go after you till they get it.
The reason it doesn't matter who was at fault is that the OP WASN'T insured and wasn't an authorized driver. Theres no way to get around that. That makes the OP liable for whatever they can get. Since OP wasnt authorized insured driver, their contention will be that the car would not have been on the road at that time in that spot.
What im supprised at is that the person who rented the car and allowed the OP to drive the car isnt also hauled into court and sued as that person was in control of the rental and should not have let an unauthorized driver drive it. The OP or the other insurance may be able to go after the renter, too.
The OP can try counter suing for the injuries and/or sue the one who unauthorizedly lent the car to OP, and that person had a contract with the rental company that they would be the ONLY driver. If the OP goes after the lender, thpugh whatever relationship they had will be destroyed. And im NOT sure the OP will be allowed to sue the lender, but the rental company may as its breach of contract.
OP contact the legal aid society in your area. If you dont know where or how, dial tge 3 digits 2-1-1. Those 3 digits inly...no need to dial an area code and no need fir a prefix, just 211. Ask to be put in touch with legal aid society for low income people
Or cough up the money somehow for an attorney to represent you. They can advise you far better than we can
Get an attorney how ever you have to, youll need one amd still may lose everything and have garnishment issued on your paycheck.
You're going to NEED an attorney , DO NOT try to defend yourself as you will most likely lose.
The person who should be held responsible is the lender. They had no business lending a car to an unisured unauthorized driver, and breached the contract with the rental company that should clearly state it is to be driven ONLY by authorized drivers.
OP take it as HUGE lesson learned, get an attorney promptly and then buy yourself a liability umbrella policy that MAY cover such things in the future. It MAY refuse if you had one, to cover you as you were an unauthorized driver.
Rental companies, contracts and insurances are a fickle matter, even WITH an authorized driver in case of accident. Your own policy covering rentals, credit card insurance on rentals rented with that card and of course tge high cost of insurance through the rental company insurer can all get confusing as to how an accident is covered as those insurance companies will all go after the weakest link to get reimbursed money they are out.
Insurance companies are in the business to make money, and will go after whomever they can to get reimbursed so they are not out money.
Its a fickle business, but in the end the company is always going to win.
So to recap again OP:
Get thee an attorney however you have to. Do not try to fivht on your own. Countersue for lost wages, pain and suffering. You might be able to get a judgment for what you will owe when the insurance company after you gets a judgment against you.
Best of luck to you, and really this is lessons learned. Hope you take that seriously to heart.
Never a lender nor a borrower be ( unless you are authorized and insured!)