I see you're struggling a great deal and I'm sorry. Your sitch reminds me of two quotes by Lao-tzu:
"Someone must risk returning injury with kindness, or hostility will never turn to goodwill."
"If you seek revenge, you might as well dig 2 graves."
Hard to follow I know, but something to think about.
Your BF says it will be over if you're not exclusive - but doesn't everyone say that? Didn't you? I think he's trying to hang on to you and the "we're done if you date" type of response is his manly, yet immature way to express his love - maybe?
Me 56 H 47 Married 21 years No children Bomb & moved out 4/07 "My feelings have changed" & "I want to live by myself". Ow Bomb 8/07 H filed 6/08 D final 2/05/10