I think you have to concentrate on getting yourself better. Right now you are obviously very stressed, very sad and you have a pretty low self esteem (you called yourself a loser). Your oldest kid is in college already. Will the other ones go to college too?

Make your recovery your priority. It doesn't sound like your kids will starve if they are left to live with their father. Use this time to patch yourself up. Show them that you are doing better.

I understand that after 19 years of a relationship it is extremely hard to start a new life from scratch, but you will have to do that regardless if your kids are with you or not.

Are you still seeing your therapist?