First and most important advice: Find Erin McGathy’s This Feels Terrible podcast. She lets people email her, and almost always writes back whether she responds on the show or not. She gets this stuff way more than me, and she might even be able to share with you the fact that having a boyfriend can also suck.
I know it doesn’t feel this way but what you’re experiencing - the most troublesome parts of it - is chemical in nature. You have a dude in your bloodstream. You’re going through withdrawal. Five months is not a long time for this kind of thing, sadly.
You might be having feelings like “I knew who I was when I was with him, now I’m nothing.” And you’re probably thinking ALL kinds of stuff about where he is and who he’s with and what he’s doing. And now we’ve got 600 apps and sites to help us torture ourselves with that stuff. Even just thinking about it while typing to you gives me a little feeling of panic, because we’ve all been there.
That’s part of the good news: you are part of a club with about five or six billion members. You can find some of those people online, I bet, and talk to them about this. It would help if they were strangers, oddly enough, because it sounds like you’re in a complex social situation where there’s friend circle overlaps and stuff, which is a big reason why it’s lingering five months. Cut down on conversation about this guy with mutual friends as much as you can for as long as you can. Find something new to add to your life, something that never existed before this guy became a thing: a TV series to binge-watch, a random subject to fixate on, something you’ve always wondered about, like “how do submarines work?” Start googling and just dive in, and let submarines or Peter Pan or Godzilla be your thing. Your symbol of how you have an identity, you have your own brain, your own body, your own control over your fixations.
If you do talk to people anonymously on the internet about what you’re going through - there’s bound to be forums for it - my advice is don’t let talking about what you’re going through turn into talking about the guy.
One more thing: this stomach turning feeling, this panic, this sadness…that’s not what real love feels like. What you’re feeling is powerful, but so is heroin and morphine, and those aren’t love. I also swear that it will go away. There’s no telling when, there’s just going to be this day when you wake up and magically do not give a shit. And a few months after that, it’s actually going to be laugh out loud funny to you that you felt how you felt. I have never felt more comfortable promising anything to a stranger.
Hang in there. Also watch Rick and Morty on Adult Swim in December and Season Five of Community in the year 2014 AD.