How do I get over my ex, & is he even worth crying over?

Ok so its like this, Im 18, him and I have been dating for 9 months, and I thought he was the love of my life. In the beginning things were so good, but then I started uming, but I felt as us being together and being as one I had a right to ask questions... he'd always say if you trust me you wouldnt be asking these questions, so then he broke up with me, 3 times in a row.. I just ended us officially 5 days ago. I keep thinking about all the good times we shared, but there are some bad times too. We cut each other off or good, people are telling me that now is the time to focus on me and my career and I agree but sometimes I just start crying because I reminisce.. What do i do and what is the fastest way to get over him.