A very good start!

a few things...

Your mom isn't obsessed with "sex" as much as she is obsessed with ownership of you. No woman , virgin or not, will ever be good enough for her boy. Don't believe the whole "i'll disown you" drivel. She is just trying to keep you stuck.

As for the finances and her making a list of what she believes you owe her, don't hold your breath. Why would she help you to move on?

My advise, for what it is worth;

get a mail box (so she can't fiddle with your mail)

and most importantly, MOVE OUT .

If it means sleeping on a friends couch on the weekends while you get yourself sorted, start there.

Do not delay moving out until your "debt" is paid, because it never will be.

Keep going to the pool, even if she is there.

Do not allow yourself to become isolated. Stay in touch with people , you ex girlfriend in particular.

Finally, do not share your plans with her. She will try to debate the issue and bog you down with the super glue of guilt and toxic shame.

stay strong