I had a similar experience growing up: completely white town, minorities counted on one hand, zero african-americans. Not a single gay person to be found. Not until I attended college did I meet an african-american, or any non-native english speaker. Muslim? What's that? I was raised to believe african-americans, gays, and communists are bad, evil, flawed, un-welcome.
In junior high school, a friend invited me to attend a church social event near a river one night. Some of the guys put together a big, makeshift cross out of lumber they brought with them and planted it in the ground. We had a small bonfire going, and then they lit the cross. Several of the guys in the church put their Sunday robes on...then they pulled hoods over their faces. Yeah, KKK.
I knew a policeman who drove drunk all the time. I knew a teacher who bought high school students liquor many times. I knew a peer in high school sleeping with that teacher. I knew girls pregnant by 11th grade. I knew domestic violence that happened in my house, in my friends' homes, and in the homes of people I barely knew. In a small town, most of my friends and I experienced separated families through divorce.
My experience could be unique, or it could be quite common. At any rate, by the time I finished college, I needed to leave.
The midwest isn't all bad, but I saw some of the worst it has to offer.