Hello,
suffering from loneliness is hard, especially when you are surrounded by people you've known for a long time. I can relate to this, because I felt like this in my past.
The way I think and feel about it has changed. So I would like to share with you in what way.
I felt lonely and disconnected all through my late teens and early twenties. You were talking about 16 personalities of MBTI and INTJs. I identify as INFP. I am pretty sure both my parents are xSxx types. But the point I would like to make is not about the test. Its about the fact that I felt different and misunderstood. I found MBTI years later and felt confirmed about how we differ. But it has helped me try to take my parents how they are. In my case, looking back I feel like I was the one missing out... Same goes for my friendships. I was the one not letting people close, although I craved deep connections.
Offcourse, there will always be people with whom you can connect much faster and with less effort.
Now this may sound easier than it is... or it may sound way too obvious, I don't know. It took me years to figure out the theory and I think the practice is a never ending process.
What I want to say is just that I found a way to get closer to people by showing more interest in what is bothering them and by sharing more of myself.