Sweetheart, you need a long term plan, because this is unlikely to get any better. As you said, you married the wrong man and he won’t change. Don’t beat yourself up - instead start ‘putting your ducks in a row’.
Start by addressing your compulsion to self harm. See your GP, get counselling, seek out support groups.
Work on your self worth - The Six Pillars of Self Esteem is a good start.
Start saving a bit of money. Get small sums of cashback and put it in an ISA.
Plan to get back to work as soon as is feasible and redouble your efforts to save and become financially independent.
Keep copies of all financial paperwork - his P60s, pension, bank statements, etc
Start educating yourself about the divorce process, particularly division of assets - Wikivorce, Divorce for Dummies, family solicitor websites.
Once you feel ready, see a competent family solicitor and file for divorce.
This must seem an insurmountable task right now, but you’ll get there, one day at a time.