Should I be afraid to ask him?

I dated this guy for about four months and he broke up with me a month ago because he wants to focus on school.He told me that he is taking 18 credits this semester as well as taking two night classes and an internship over the summer. He says he still really likes me and wants to be friends but feels bad because he doesn't want me to feel like I was being used. We did not have any form of sex since we both agreed to take things slow. He sent me a text about three weeks later and mentioned how he has been second guessing himself on breaking up and that although school has always been very important to him an still is that it's not going to stop him from thinking it was the wrong decision (his words). But he didn't mention wanting to get back together in the future. I'm crazy about him and although I want to give him his space I also want to ask him if he ever wants to get back together. I'm afraid of being rejected and it ruining our friendship. So should I ask or just wait and see what happens?