I'm assuming you're still in college. I'm a male, I'm in the same situation as you are. I dropped all my friends for my girlfriend, only to end up dropped myself two years later. First things first, get your feelings together first before you even try being social again? I had a two month phase where I just took time to heal and get my feelings together, if I talked to anybody in this phase, I would only want to talk about my ex and it made me very unpleasant to be around.

After the two months, I began making myself look more approachable. I hit the gyms, I got into the best shape of my life. I began doing things I never would've done. I took on this new mantra, do new things, live a little. A life of constriction is not something I was interested in anymore. I got a badass shark tattoo on my arm with a semi decent backstory behind it (I hated tattoos before but one morning, I woke up and just decided, today is the day to get a tattoo). I started playing pick up sports with male friends (something I'd been afraid of my whole life, I was always chubby and I didn't even know how to throw a football until three weeks ago). I started going to parties again with friends, I even tried my hand at dancing.

To be honest, my social life really hasn't picked up yet. It's still summer and college campuses are dead at the moment. But I've done the best with what I have. I started making small talk with co-workers in the Dining hall, and since then, I've become good friends with a handful and we have nights out.

I guess my TL;DR advice to you would be: If people don't seem interested in interacting with you, it's because of the way you present yourself and behave. Get your feelings in check, make yourself into the pleasant person you'd want to hang out with, and reap the harvest of your hard work?