Lately, I've been feeling really sad. There's this guy, but I don't think he feels the way I feel about him.?

First off, I'm 17 & I'm gay. There is this guy, we've been on & off talking for about 5 months go, this past month in a half, we've gotten more serious, we would text literally everyday, but lately we haven't, like these last 2 weeks, it seems like all we say is hey, ask eachother sup & that's it. We have the same friends, & hang around one another, so I see him often. He & I aren't together, but we're like friends with benefits. It seems the only contact we get is when we're alone, which isn't often. We've made out & done other things... but after we do those things, we barely talk to eachother. I feel like that's all he wants, someone to mess around with... I want so much more, I've fallen hard for him. I'm always thinking about him, & it makes me sad, as I have many doubts, or I feel like he doesn't see me the way I see him. I feel as if only he can make me happy though, but when we don't text & stuff, I hurt. I'm always thinking about him, & it makes me so sad. What should I do? How can I stop being sad, & just be happy again?