being used??

So I have this guys that I have a super huge crush on. He was my first person to have sex with. That was about a year ago. But over that past two summers all we did when we hung out was have sex. I moved a couple of months ago to a different town so we couldn't have sex every weekend like it was before. So he got distant and only contacted me when I messaged him first. Then he would only ask to hang out after like a month or like 2 weeks after we hung out last. But when we hung out we had sex. But then right after we have sex he would take me home. I feel like I'm just used for sex. Before we would have sex we would go to his house and sit in his room for a minute before he would ask me what I would like to do. I'm still kinda new to the whole sex thing. I'm only 17 so the first thing my mind thinks is sex and I think he knows that. He always finishes and doesn't exactly try to give me an orgasm. I haven't had one yet. He's also 21 so I'm not sure if the age difference is a factor.