I want to have sex but I'm not in a relationship, so...?

I had a long term boyfriend a year and a half ago, but I haven't had sex since then. I'm a 19 year old girl in college and I want to have casual sex because (obviously because it's sex) but also because I feel like I'm wasting my youth. Having only ever had sex with my long term boyfriend I was in love with though, I'm worried about what emotional repercussions there might be. But overall it's been a really long time since I've had sex and I keep leaning more and more towards just doing it. Would it be a really bad idea?