What is wrong with me? (What is this?)?

I'm rather lonely, I constantly have a yearning for peoples company and someone to talk to, I don't like being on my own, and get depressed and upset when I am. Especialy when I'm emitted from certain events. But at the same time, I want to be on my own and I enjoy it and choose to stay on my own. Like my uni flat will hold a flat party and I'd just feel like I'd much rather stay in my room than socialise. Which makes me think possibly from time to time, people might not mention a particular night out because they assume I wouldn't want to come. But I feel like I'd prefer to be a gremlin and only emerge from my room for food, but I still have this yearning for absolute company. I have plenty of friends and go out a fair bit. But, Why do I do this? Choose to rather be on my own, when I really would like a couple people to really be there all the time. Like, I'm confused. Is there something I have? Like.... mental health section..? :D