I can't figure out why I like being alone but hate it at the same time?

I'm 25 years old and I've lived a very isolated and lonely life. I had a pretty turbulent childhood having to endure an unstable family life and I had little friends in school because I was picked on regularly. I don't suffer from low self-esteem and I've been told that I'm an attractive person with good qualities (not bragging). I was diagnosed with manic depression last year, but fortunately I don't suffer the severity of the disorder that most individuals do. I rarely have the highs (mania) and I mostly suffer from the lows (depression), but the medication I'm on keeps it in check. I socially withdrawal when I start to suffer symptoms to avoid any sort of damaging behavior or to avoid damaging friendships. I appear normal to everyone else. Anyways, there are days that I absolutely hate being around people. For example, if I go hiking or for a walk I get frustrated and agitated when I see people hiking on the same trails, but other times I don't mind at all. Sometimes I'll walk miles into the woods even when its snowing out just to hear the sound of silence except for the snowfall or the wind blowing past my ears. I absolutely love it. But, there are other times when I'm with my friends and I look at them and see the relationships they have with others and I find myself yearning for that feeling. I don't get it though. I don't understand social relationships. People tend to frustrate me with their ignorance, hate, and constant gossip. I feel like there is no originality left in the world. I've heard and continue to hear the same stories when I try to be social and go to the bars or small social gatherings. I hear the same topics discussed over and over. I can't seem to find interest in any girls that I meet. I feel like most of them are plain and dull. I just see the same thing in all of them . . . Ugg boots, designer jeans (don't get me wrong I like some cl), wearing heels in unnecessary settings, following hideous fashion trends that most men find unattractive, cell phones and constantly texting, gossiping about the same topics, etc. I just want someone that is opposite of mainstream culture. Am I just overly sensitive to social interaction? Do other people feel the same way? What the hell is wrong with me?