I'm sorry you're feeling shitty. I don't know if I have any great suggestions, but I think you need to get out of town, if only for a little while. Take a vacation, get something fresh in your mind, get out of the midwest in the godawful summer. But it sounds like you should probably find a new place to live pretty soon. Is anything keeping you there besides inertia?
BTW I don't hate the midwest - I just took a brief trip to Minneapolis and was reminded of why I love the city so much sometimes. Maybe you should move there - it's relatively inexpensive and has interesting and friendly and nerdy people. Seriously, all my old friends play DnD now, even the ones working at fabulously hip cocktail bars. Maybe you don't have awesome social skills but it's honestly never been easier to be a huge dork and find people to hang out with. I went to a town of 900 people a couple months ago and a friend of mine had organized a game night at his art gallery there.
The standard suggestions - therapy, exercise, volunteering - are all fine, but I'm pretty bad at doing those regularly myself. But I can tell you that the frustration will only get worse if you don't take some kind of positive action.
If you want a book recommendation, Journey By Moonlight by Antal Szerb is a wonderful novel about a mid-30's weirdo having a crisis of nostalgia for his weird teenage years and deciding to wander around Europe instead of going on his honeymoon.
I hate to recommend it since it rips off artists but honestly paying for Spotify made me really excited to hear tons of stuff that I'd meant to hear. I'm jaded now but it was fun.
Good luck. You're a good guy, and deserve to be happy.