Sex and intimacy

Hey there /r/gay, I've got a series of questions. (Throwaway for outing reasons)Info: M 24, consider myself bi. I've been with both men and women. Never really considered myself a particularly sexual individual - don't think about it/don't masturbate anymore. More recently I've been thinking about pursing a long term relationship with a man. All my previous long term relationships have been with women. The men I've been with haven't been the best partners - party/drug fueled, manipulative or only there for sex. Never "dated" a man for more than 2 months, granted most relationships in college seem to be like that.Questions: Are there any sites for long term relationships in the gay community? I haven't tried Grindr but I haven't heard good things in regards to lasting relationships.Healthy sexual practices?I'm a bottom as far as I can tell. But the last time I tried anal it was too painful to continue. How do you easy into that?Lastly, the thought of me putting my dick in someone's ass doesn't do it for me. I'm fairly certain I couldn't even get erect if it were required of me. I've began reading into bot/top trade offs and it seems that it's fairly accepted that everyone likes variety and thusly tops and bottoms will switch it up sometimes. I've been in a relationship with a sexually selfish person before and I don't want to become that by saying that I could never top. And I guess I'll never know until I try but mentally putting myself there makes my dick shrivel. Are there people who only want to top? I mean, I'm sure there are but how common is it?If this isn't the sub for this or if there is a sub where I would find more answers, please point me in that direction.Thank you for you time!