Hmm. All I can say is my opinion:
(1). I've lived, for at least 3 months, in large and medium sized US cities. Tulsa (OK), South Bend (IN), Indianapolis (IN), Pennsylvania (PN), Miami (FL), New York City (NY), and Durham/Raleigh (NC). Of course, I've visited dozens of other major and medium sized US cities.
(2). Conventional wisdom is true. You're only young once. You want to be in the largest, wildest city you can for at least a decade of your life. You can't party in NYC or LA or Miami or Chicago when you're 50. Do it now.
(3). Conventional wisdom is also true that despite the pictures, propaganda, travel boards, and rhetoric, most places are decent and livable. I always found friendly, nice people, and jerks in every city I lived in. It's all about who you surround yourself within the city and where you go.
(4). Conventional wisdom is also true that despite the fact you can find friends and fun anywhere, some places ARE better than others. This is because there are simply more opportunities, more people, more chances, more everything in some cities versus others.
(5). I recommend you visit any city before you live in it. Even then you won't have a REAL feel for how it is on a day to day basis. What's a mere nuisance on a trip turns into a deal-breaker after 6 months. But it's better than nothing.
(6). Personally, I recommend the following cities to a young gay male such as yourself, and for the following reasons.
(a) NYC (it's true, the city is f-ing amazing. I go out and still see restaurants, bars, clubs, and entire neighborhoods I've never seen before. Literally, if you ate and partied at a different place everyday, you could not patron all the places the 5 boroughs has to offer before you die. Fast-paced, but manageable. Expensive. Opportunities. People. Small housing. Excellent subway/buses, no need for a vehicle. Arts galore. American Ballet Company. Lincoln Center events. Columbus Circle. The Village bars. Hell's Kitchen's nightlife. Central Park. Coney Island (only a 40 minute 1.50 train ride away from Manhattan). Every pop/rock concert you could imagine. The proverbial center of the cultural world.
(b) Miami. Perfect weather (except a few months of rain a few hours everyday). Amazing beaches. Nightlife that rivals NYC. Miserable "downtown" (the shops are like a sprawling flea market). Slow service. Decent above ground rail and bus system. Taxis can be hailed most locales. Decent Cuban and Mexican food, but not as impressive and easy to find as you might think. Feels like a constant vacation. Large number of people only speak Spanish. It doesn't feel like "America." It feels like a port city on a Caribbean cruise.
(c) LA/San Fran. I know these are two cities, but to me they're the "West coast" and interchangeable. From what I gather visiting them, LA is more shallow and everyone is obsessed about the entertainment industry. San Fran has more LGBT heritage, more down to earth (but no less attractive) guys, and a more welcoming feel. LA requires a vehicle, San Fran doesn't. San Fran has HIGH housing prices, LA isn't far behind unfortunately.
(d) Chicago. I've visited Chicago so much I might have spent 90+ days in the city at this point. It's solid all around and is a huge gay mecca for midwestern guys not wanting or afraid of the coasts. Boystown is really run down in parts, but I walk it at night without fear. No vehicle necessary if you live in the city, but it's cold more than 1/2 the year. I mean real cold. Colder than Ohio cold. Top notch cultural opportunities (ballet, philharmonic, concerts, art exhibits). Restaurants galore. Fewer "clubs" and more smaller bars, which isn't necessarily a bad thing, just a different scene. It can feel "fratish" at times, like Boston.
I'd also consider, Atlanta, Philadelphia, and Dallas. Maybe Nashville if you're really into the country scene. It has a surprisingly vocal LGBT population.
Good luck! You're young, everything will work out sooner or later.