Struggling with Casual Sex

I feel like I’m going crazy, now I know casual sex isn’t my thing. I met this girl on Tinder who happens to go to Carleton college, the college right down the street from mine and at first we decided we would just be friends. But the next semester she said she wanted to have something casual, so we hooked up multiple times this semester. I know I’m too emotional to be in something like this since I get attached really easily. I notice I get super depressed after every meet up because I know we’re not in a relationship, and she won’t call me for weeks. I’m the one always reaching out because I caught feelings in a “no strings attached” situation. I’m scared to sit back and watch it fall apart.