So there is this guy?

Ok so I really like this guy for a very long time, but I have a problem I don't know how to to tell him how I feel. We did go out my senior year of college and it was great. I ask him today about our past relationship and all he told me was that we fell off. I want to go back how it use to be, but I do not know how to tell him. 
The fear of rejection is getting to me and I do not want to get hurt.