You probably don't have any "trust issues." There are circumstances where it is appropriate and mentally healthy to withhold trust. That's the kind of circumstance you are in right now. He may not have actually cheated on you, but he is showing that he is not committed and wants to keep his options open. You'ld have to be kind of dumb to totally trust a guy with his behavior. Mistrust can be very healthy. It's what can keep you from being made a fool of.

Sure, he probably has done some nice things for you. That's not the issue. The issue is that, after 18 months, you expected your relationship with him to be exclusive. He wants to keep his options open. It's not really a case of who's right and who's wrong. It's a case of not being on the same page about how committed you both are to an exclusive relationship. Committed guys don't go out for drinks with other single women. Not if they want their relationship to last. It sounds like he wants to keep a woman devoted to him, while he shops around to see what else is out there. That's not fair.

It will take time, but the heartbreak will lessen. Try to be around other friends, so you don't just wallow in misery. Eventually, you'll meet other young men. One of them will be looking for what you want.