You are worried, take it slow, one course at a time for a while until you feel up to taking more. Maybe even consider a non-credit adult-ed course to take the grade stress off the learning.
How do you learn best? What gets in your way? What would help you to succeed? We each have a style of learning, some can read and do, some need hands on, some of us are visual learners, others learn more using other methods.
MH issues always complicate things, but do not have to make it unattainable. You really can do this, maybe just not the way you think you "should"...
Don't give up. PM if you want to.