Trying to get my ex back! Help!

I am a leo woman and I was in a serious relationship with a Cancer man for almost 2 years. Sometime in the middle of the relationship he broke up with me and exactly 1 month later he came begging me to take him back. We've had our share of arguements and everytime I threatened to break up with him he came crawling back. Once we began fighting and arguing sooo often I decided that we really needed time apart and I broke up with him. The next day I called him and picked up my stuff... he admitted to me that he was hoping I was actually coming by to get back together with him. He even called in sick to work because I guess it had a huge impact on him. After a couple of months passed I realized I was in love with him and we went out for coffee and I tried to get back with him. He told me he isn't sure what he wants and he doesn't know if he still loves me.

After being broken up with him for about 6 months I got with a new guy who I was with for only 4 months. I broke it off with the new guy because I am still crazy in love with the ex (cancer). My ex knows that I am single now and we talk once in a while but only when we run into one another on campus. I'm dying to get him back but I'm afraid of getting rejected. What should I do. How should I approach everything? Ohh and I forgot to mention his parents no longer want him to have anything to do with me...