Ex boyfriend?!?!?!

So me and my ex dated 1.5 years long distance and it was brilliant until I did my gcses. He left me and said that he hated he had to do this but he thought it was the best. Initially I hated him but soon I realised that I wanted to split up for a bit too. Its been 4 busy months now and he has messaged me and i think is going to want to rekindle things. I am stuck because he really did hurt me but I think of him all the time and do miss him and have love for him. I am doing okay but I am often caught thinking about him. What should I do?!?!?!?! Xxxxx