OP, I think several things may be going on here. As mentioned, you may have fibro or arthritis. Eating poorly and no exercise make these things worse, and also lead to depression. You have to take baby steps - get a diagnosis on the tiredness, etc. Change your food habits. In addition to what has already been suggested, there are really healthy frozen meals on the market now that are low calorie with natural ingredients and you just toss them in the microwave. Much cheaper, and healthier (and easier) than the fast foods. Plus the bagged salads and other prepared foods in the stores that have been suggested. At least do this if you don't want to full-on "cook". The fast foods may actually be a huge part of your problem. They contain a lot of sodium and ingredients that are not good for you. Also, DO NOT eat junk foods because they can exacerbate ALL of your problems. Find a support group, that can help also. There are many on-line.
We are going into a new year, you can do this!!!