I've always been like this as well. I have all sorts of solitary things that I enjoy doing, and that time spent alone recharges me for the other parts of my life. But, when I'm alone too much, I get lonely and that makes me unhappy. But, when I'm trying to maintain a social life I don't get my alone time as much and that makes me unhappy.

Fortunately my wife is very similar, so it's a good fit on that level. It can just be really hard finding a balance while still being a good friend to my friends.