It sounds like your main issue is abandonment or not being able to count on people, or them not caring. I mean I am old now compared to most people on this site, and you really can't count on people. The friends I had or few women i dated who were popular, those types kind of developed a fake personality to keep everyone entertained. It could be that you are trying too hard. Most popular people with friends don't have any close friends really, just a lot of superficial friends and relationships. I have lived alone for 20 years and it is not some picnic. It has actually been mostly a nightmare, the few women I had over here were disasters to deal with in different ways and none lasted. My point is, whatever chaotic situation you are in with your mother or brother might not be that bad. I would kill for any kind of action right now, even if that meant a ton of family running around and fighting.
Anyway i can relate to having no friends etc. I had a good friend for 7 years who cut me off about 9 years ago. i have resigned myself to the fact that people are slimebags (to censor myself) and everyone is out for themselves. I think for people like us to have friends, we would have to not come across as needy, while developing a fake fun, happy, peppy personality, and devote a lot of energy to that. On some level, we almost need to use people and disrespect them back now, as a way to even the score, even if that is not a smart path to take.
I really think I am the type of person who at his funeral will have no one show up but random strangers so it feels more normal. It really for me comes down to, when i develop something with a woman or a friend, they don't value me and eventually cut me off. The world we live in now, especially with dating sites and facebook everyone is expendable and there is always the next best thing around the corner, or so it seems to people