I suck at finding people I genuinely enjoy being around

I'm an attractive guy, I work at Starbucks, ride a motorcycle and have pretty much anything I could ever need at 18, but the one thing I truly lack is human connection. I have one truly dear friend. Recently my girlfriend broke up with me and now I honestly just feel so fucking alone and the thing is I was feeling alone before she even broke up with me. The one thing that kills me about it is that she's one of the only people I've met besides my best friend that I genuinely enjoyed being around. So what the fuck am I supposed to do now. Heartbreak is a bitch. Heartbreak on top of depression is fucking unbearable. I feel like an introvert that wants very badly to be extroverted and loved by everyone, but for the life of me(with the exception of my friend) I can't manage to get close to people unless I'm having an intimate sexual relationship with them. Also have been having thoughts of suicide, but I know I'd never go through with it. Any advice is appreciated.