Hi Ventilator,
I'm late here, and too busy to read all reply. So I may be repeating what the others said.
How deep is your relation with her? Staying together is certainly not necessarily a good moral. But if you have a deep relations with her, it could be hard to leave.
You know you are possessive. That's good enough. I am a skeptic but I can acertain you that meditation will help. Well...may be you need some extra input, some inspirations, though. But meditation will be able to help with that.
I was ultra-possessive. But I changed dramatically, and effortlessly. Maybe I didn't change, I just realize more.
Maybe you can start by understanding her more? You don't have to force yourself to accept anything, nor to leave her. Try knowing her friends if you can. You said you are possessive. Do you afraid of losing her or at least her attention when she hang out with friends? If you know her friends, you may start to understand why she likes to hang out with her friends. You may know what her needs are. Paying attention to her needs seems to be a much better idea than forcing yourself. You can still be yourself. Yet when your expression of love change into a more positive one, we don't call that "possessive".
If you express your love positively, the rest is much easier. You will not regret, even when you have to leave her at last.
Alvin
