OK, here's my $.02.
I live in the far NW burbs after moving from the city with my (now) partner. Ironically, we have more gay friends here than we did when we lived in the city; probably because out here it's a lot less clique-ish. But you have to access what's going on around you where the gay people are.
We have a recently single friend who went out and joined a gay bowling league in Des Plaines. He doesn't particularly like bowling, but it's only one night a month and he's met tons of other gay guys. He dated one for a while, and has had some dates that were arranged with friends of guys he befriended there. Do you remember the old insurance commercials for MetLife? The tag line was "Get Met, it Pays." That's true in dating too. Chicago has a TON of gay athletic teams and leagues for almost any sport. You won't have to worry about people knowing you're gay if you join the all-gay football league. For true.
As for being str8 acting/looking. Me too. I have friends for 20 years who tell me they're still waiting for their gaydar to go off. Sigh. That said, it just means that when I was interested in meeting somebody I thought was hot, I needed to put in a little extra effort at letting them know I was interested.
I'm a firm believer that you can get hit on and get sex anywhere. You can connect with a hook up at the grocery store if you're paying attention. I watch people's eyes (where it's the hardest for them to lie) all the time, and you know what? I think I do a pretty good job of figuring out who is interested in who (including me) most of the time, and I'm nothing spectacular.
Since this is a real jock forum, and you're probably the gym type, I guess I'll offer this advice: Go to the gym at the time when the type of guys you are most interested in go. At my gym that means early morning for corporate, afternoon for retired, 4-6 p.m. for the late teen/college, and after 7 for the young professionals. Then, just watch surrepticiously. Don't look for who is looking at you (they'll look away quickly most of the time). Watch people to see who they're watching. You'll get a good idea of which ones gaze a little too long at the guyz or their bodies. And once you've figured that out for someone you are interested in, you can invoke the magic word ("hi", or derivative, "hey", or if you're younger, "'S'up").