How, I wondered as I read this, did the situation get to where the daughter is taking care of the mother instead of the other way around? You didn’t mention if your mother is mentally ill, incapacitated or a substance abuser. You didn’t indicate whether the bad decisions around financial matters happened only a few years ago or are a life long pattern. And you didn’t indicate if there are other family members who can be of help. Without that information, there is a limit to what I can suggest — except this:
At 22, it is appropriate and normal for a young person to leave home. You needn’t feel apologetic for wanting to do so. From what you shared, I doubt very much that you can “make her understand”. She has no reason to “understand” if understanding means she will have to behave like the adult that she is. If she has a tantrum and pushes you away, it’s on her, not on you. It sounds to me like the “relationship” you have is very one-sided. To have a real relationship with her, based on love and respect, not guilt and manipulation, requires a major shift in how the two of you relate.
This is all based on an assumption that your mother is physically and mentally capable. If not, it is way past time for you to get some help. She may need to be evaluated to see if she qualifies for state services as well as treatments for whatever is amiss. If there are other adult members of your family, it is also important to inform them of the extent of your mother’s dependency and to ask for their help to extricate you from being her primary provider. No extended family? Then turn to your community resources. You might find help at the local Senior Center, for example.
You have every right to be very proud of all you have accomplished so early in life. You have been a compassionate and helpful support to your mom from the time you were in your teens. You won’t be able to leave if you feel like you are abandoning your mom. But, with some thoughtful planning and with both family and community resource help, you can and should move on with your own life. After all you’ve already done, no one will fault you for doing so.
I wish you well.