What does this mean?

What does it mean if a guy you have known for a while, keeps coming back into your life but won’t commit. We have went out on dates, we are both attracted to one another, made out etc. but not sex- I have made it clear that I am hesitant to have sex with him because I have feelings for him and I want more. He also seems hesitant of that too (sex) and claims I am the one person who he wouldn't want to let down. He knows I am not a casual dating type of person- my life has been school and work focussed. I love to have fun but I need to be sure about someone before I invest in anything (like have a connection or friendship). I feel that our relationship developed over time, he is someone I feel comfortable with him and I was able to feel that I can open up. I feel like we do connect when we are together (but maybe I am just delusional), and I have tried to communicate with only the intention of understanding where his head is at. He says he doesn’t want to hurt me or let me down. It’s frustrating because he re-initiates contact every so often and then all of my feelings come back because I care about him, but then he will become distant. He has been in relationships before. Do guys get into relationships just for sex and are scared to be with people who they actually connect with? Is that a thing?? or is he just actually not interested? Any new insight is appreciated