You'll come to a point, most likely, where you'll be able to love your mom but also realize that she needs to help herself. There's nothing you can do.
Let her know in various ways that you care for her, but let her deal with her own problems. Send her flowers, leave surprise gifts at her door, write her a letter, whatever you feel like doing that she might enjoy. But let her fight her own demons, and don't allow her demons to intrude upon your life. You can listen, you can be a shoulder, but keep your opinions and thoughts and suggestions to yourself unless she directly and specifically asks you for those things or for help.
If your mother loves you, she'll want you to have a full and happy life. She won't want you worrying about her problems. Mom's - I'm a mom - just need to know their kids are happy and healthy and to feel loved by their children. We don't want our kids taking on our challenges for us. Most of us don't, anyway.