Low self-esteem and loneliness

Hi everyone, 

I am really struggling with low self-esteem and loneliness. I'm 32, I was diagnosed when I was 30.

I have always known that there was something 'wrong' with me, and have been trying to get a diagnosis since I was 18, but have been fobbed off by doctors and just given antidepressants (they work for a while but then stop working and I have to go up a dose, and when I reach the highest dose, it starts affecting my IBS). I have always struggled with holding down jobs; when I was younger, I was able to hold down a job for 6 months to a year, but as I got older, the time got less and less. I am now on benefits, I haven't worked for 2 years now and I'm studying at college online.

I also have a lot of social difficulties. I've moved around a fair bit, and have a long history of being ostracised by groups of people, to the point where they warn others to stay away from me because I am a "psychopath". I do have good friends somehow, but they are very few in number. I am scared of meeting new people in case they also ostracise me or reject me. I've also had pretty rotten luck with relationships and I've given up hope that I'll ever be in a serious relationship.

I don't have particularly good social skills - I have been criticised for "oversharing", my meltdowns don't go down so well and people generally find me weird and odd. I also have a pretty childish sense of humour, which people find annoying.

I'm not sure what I'm doing wrong and how to combat this... at this point of my life, I think it's safest if I just keep to myself (which is kinda boring and depressing). Years of failure and social rejection have chipped away quite a lot at my self-esteem.