How do i get over my ex?

I dated this girl for 10 months and she was my first love, even tho so many things were great about her and our relationship, we couldnt trust each other for various reasons, which was something that i decided i couldnt deal wit because of the emotional strain. about 3 1/2 months ago we broke up, were still messing around for a couple weeks, stopped talkin for about 2 weeks, then one day she called and i asked her to come over and we had , after that we had an arguement in which she stated that she didnt like me as a person anymore, even tho i kno that it was said out of anger, i decided that the only way we would get over each other was to be dead to each other. i havnt seen or talked to her since, jus one text message where she stated i was still in her heart and i responded that she was too. but even tho i kno the pain i'd feel bein with her again because of the issues we had and couldnt resolve, i cant stop thinkin about her and missin her and its been almost 4 months now. and ive been datin other girls and had wit one and heard through the gvine that she had done the same, but none of that stops me from lyin awake at night missin her, wat should i do or how do i go about this?