Sounds like a grueling but worthwhile weekend. Huge respect for facing this and being so caring and honest with your bf.
Couple of observations from inside the male jealous brain.
- This will be very hard for him to deal with. Dealing with issues like this is not something we get any instruction in unless one has particularly self-aware parents. It's like giving a complex maths problem to somebody who never studied maths at school. Some people will eventually work it out by themselves. Many will not or it will happen too late. Help him find a way to work it out.
- might be a good to start with this and work throught it with him - http://www.xeromag.com/practicaljealousy.pdf
- maybe none of the above works for your bf but try and find a way.
If he doesn't work through it the danger is he will find a way to deal with it that still causes him plenty of pain but not enough to leave you.
Think of it like a stone in your shoe. If it's too sore you just can't ignore it anymore and you have to stop. But it can be not that sore and still cause you enough pain to be forced to limp along.
Help him find a way to take the stone out of his shoe and it will be one of the most wonderful things you can do for him.
But ultimately you can only do so much - he's got to want to.