I was crushing on him, but he was just using me, I think?

So, he texts me and was all "i'm happy" and I knew immediately. it was about a girl. So i said, "lemme guess, it's about a girl." and he said "yeah, she likes me like i like her" and i sighed internally. Oh well, right? I'll just have to back off. But then he kept talking about her and everything time he said something, it felt like... he was piling bricks on my head so that I felt heavy. But I decided it was for the best, because some other guy likes me. Then it hit me, he was only talking to me, because she wasn't home. This was all texts, by the way. He's using me, which hurt even more. I've once stolen a girl's boyfriend but I didn't like it... the way it felt. what should i do? should i stop talking to him? i seriously don't know what to do, he's the only person who cares about my feelings... yet he's the one who made me sad. i was almost crying, feeling like a wimp. why does sh*t always happen to me? seriously... help...