What should I do?

Hi,

There's this guy that I really like and we have been together for a long while now, he sometimes flirts and talks to girls so I can't really trust him alot. He said before that if he gets into uni, he will really make me his priority and not flirt with other girls anymore.

Now that he got into uni, I sort of feel different about him, maybe my feelings for him has almost gone now. Maybe its because I know that when uni starts, it will be so much easier for me to lose him because he is so easy going and can strike up a conversation with just about anyone.

So I've been ignoring his calls and not responding back to him on social media. He's now started emailing me to get a response but I just don't know what to do. I want to be the one to end things before they come to an end and he no longer thinks about me instead of continue to keep it going but knowing that I will lose him soon and the possibility that he will cheat on me since I am not there with him.

Can someone please give me some advice. Should I listen to him and do what he says that now he got into uni, he will really try to be there for me and spend time with me, or do I just let him go as I will lose him at some point since as uni its so easy to meet people and he is bound to forget about me?