Tell me what bothers you the MOST of yourself.

I would let people take advantage of my good nature until I said no more..

i self sabotage a lot.

A brave admission.
We all lose access to memory as we age, it's the accessing memories which is the issue, not the memories themselves.
Methods of travel into the memory are worthwhile
Plus, ensuring that when you want to remember something new, you concentrate on it sufficiently for it to pass from shot-term into long-term memory.
And if you put things down and forget where, do t put things down any-old-where, put whatever it is somewhere specific, and pay attention to where it now is.
Better to always put things in the same places.

I'm sure there must be an Internet site with guidance on all this, but I haven't tried to find it yet.

The low confidence is probably an upbringing issue.
Talking it all through might help.

Possibly treat life as a game, win a few lose a few, forget lots!
Or as a play, to be rehearsed and improved on.

I slept around in my youth through lack of confidence and low self esteem. If someone showed interest id do whatever. Absolute madness when i think back. But tbh most of my life has been absolute madness. Its good u are not ashamed or afraid to admit who and what u are and have been. Respect to you ☺

I have made positive changes to my life which got me unstuck but I still hate that I know I need to lose weight and exercise and I still find reasons why I can't or won't.

i used to get too consumed by others problems and let it effect me . I no longer do this .

I care WAYYYY too much about how certain people view me.