Hi MR, huge respect to you for your 3 years clean, especially while living with an addict. Its a sad situation when one half of a couple is able to recover while the partner can't make it. Don't let anything come before your recovery.
The part about his possessiveness is a real red flag, and could become dangerous, especially now you've left. I'm glad you're a long way away.
I know it's hard, but why not give yourself some time to gain perspective on what's happened? I think over time you'll be glad you left when you did.
Very few 25 year olds have everything in place, but if that is your goal, start now. The days go slow but the years fly by. Work out what you want to do with your life and go for it.