I had a fwb for a couple of years it suited us both as neither of us wanted a full on relationship at the time but I inevitably fell for him and realised this when he mentioned wanting to look for a more serious relationship in the near future. He didn't feel the same about me and in fact treated me quite harshly when he found out how I felt and ended our friendship completely. In fact when I look back he didn’t really treat me as a friend at all for probably the last 6 months and yet I still can't get over him. I have tried moving on but he's always in the back of my mind and I'm so upset that I lost him not only for the sex but also because we had been such good friends and shared so much previously and now there's nothing at all. Why can't I just suck it up and move on?