I've hit a fork in the road.

I do love my boyfriend and who he used to be, but I don't love the person he is turning into. Shouldn't a relationship lift you up when your down? Should it relish in the mistakes of the past whether they were apart of them? Should you stick it out and indore the name cling and ridicule in hopes that person will "come alive" again? What do you do if you need to leave for your emotional well-being, how do you find the strength to realize you deserve better or do you deserve what you get?