What are we ???

So i met this guy and at first we talked a lot and where really got to know each other. But then he found out his mom had cancer( they cut it out so now it's a wait game) but he told me he can't really be in a relationship right now and I completely understood that and so we became friends. But that friends thing kinda turned into sex and now I barley see him at all now unless he's calling to "hang out" and I already know what that means but I really really started to like the guy but now it's starting to feel like I'm a bootycall or whatever. How should I tell him or let him down that just sex is not what I want. By the way we have been seeing each other for 5 months.