Ghosted after sex

I started hanging out with the guy I was boy crazy about all though high school (I’m a senior in college now). I’ve always had a soft spot for him. even though I knew it wasn’t the brightest idea to reconnect with him, I did. When we hung out he made me laugh the whole time and I felt so good- I had been unhappy bc of issues in my life.

Before we reconnected I wasn’t having sex bc I always feel down for weeks after sex. Long story short, me and him had sex. The day after he texted me for a bit then stopped replying. It’s been over 3 weeks and he hasn’t texted me. I know it was the classic “hit it and quit it” and I didn’t make wise decisions.. but I’m feeling down again. I’m not going to text him again bc I know it wouldn’t do any good but I can’t stop thinking about it 😕