I can definitely relate to this thread. Whether it has to do with type or not is debateable, but it is certainly an issue pretty much all of us struggle with.
Another discovery I made a while back was that I long for the company of others, but although I hate to admit it, I don't really enjoy the company of many people I know. It makes for an interesting yet very confusing problem.
Then there are a couple people I long for the attention of, but maybe they're out of reach somehow. They're far away, or close by but out of contact. Even though I don't want to, I get sad thinking that they're out having fun and making friends while I'm sitting here, working, even if that is not necessarily the case. And I want to stop working and go out to meet new people, but when I need to spend too much time on maintaining good quality of life, I get stuck socially. I try to budget my time but it still happens. Then I get uneasy because my job requires a lot of time and effort but I don't make much money, so I get scared my new friends, esp. potential girlfriends, won't understand.
One way I like to deal with it, ironically, is by going on walks outside. This takes time too, but not as much as I can leave whenever I want/need to. Sometimes it's nice to have a "special place" you can go to for a while, and just sit and think. It could be a park, a bar, a certain neighborhood bench, even a peaceful bus stop where you can sit down. And sometimes just being in the company of people, even if they are strangers (as long as the environment is safe of course), can be helpful. And being out n the world does help. As a matter of fact, this is a great cure for many problems.
However, the best way to deal with it is by filling whatever the void is in your life. I almost always get depressed when something isn't quite right and I dwell on it. Whatever my social problem is, it needs to be addressed or it will never really improve. So why not start now? Because maybe we don't feel ready. And that's OK. I think I will branch out more when I feel ready.
This feeling will probably never completely vanish from your life. But it can be minimized greatly.