And I would second Peggy's input about finding some counseling. If there is a way to not go through this alone, I think that would be good.
As far as being eaten up by sexual jealousy- what he's boasting about- is this really true, or is he trying to make people think something that's not true?
This is about you now. There are resources, somewhere and somehow, available to you. Maybe a local hospital has counseling or group support. Craigslist, yellow pages, local online resources- Wherever you can find it. Or start with the local library. Make some little, consistent moves, and keep following through. The magnitude of it all is very overwhelming right now. Take little steps- one foot forward. Then another foot in front of that one.
I've known nights when I prayed not to wake up in the morning. When I shuddered reaching for the door knob to go out in the morning; knowing that the effort just to get to this point was more effort than most people put into their entire day.
It may never stop hurting. But there will be days when you're glad you woke up; where beauty and gratitude will shine into and out of your heart.
I was in line at the grocery store tonight. There was a mirrored wall on the checkout stand. A little toddler girl was taking the most outrageous screaming delight in watching herself eating a strawberry in that mirror. She kept stepping away and then running back to the mirror and making the most primal expressions of exuberance in her own reflection. I told her mom, "I wish I was that happy at what I see when I look in the mirror." And that joyful miracle of a little girl has uplifted my whole night tonight.
Blessings like this exist in your world, too. Watch for them. They will be presented to you.