I could have written your post op.
I am nearly 50 and have come to the conclusion that my friendlessness must be my fault. I just feel like people don't like me. Never had many friends at school or university.
I have a fulfilling and enjoyable job and colleagues who I get on with OK. I belong to a choir which I enjoy and have two friends ( who I used to work with) who I meet up with every so often- but don't really have a close best friend. I never get invited anywhere.
I have FB "friends" who all seem to have thousands of comments on all their posts. It makes me quite sad to see all the stuff they get up to and the nights out.
When my DD was born I did make a few good friends. One in particular I used to see every week.
For some reason she just stopped contacting me and then I found out she had moved and hadn't even told me her new address. The last time I saw her, about 5 years ago) she was telling everyone what a true friend I was and how I had stood by her during a really tough time in her life. Then she just cut contact - didn't reply to my texts- ignored me. To this day I am not sure what heinous crime I had committed.
I think I am at a point in my life where I think I just can't be bothered with the disappointment any more. I don't bother making friends as it's too painful being let down.
And to the poster who wonders who would turn up for their funeral- apart from family I don't think I would have anyone.
Glad to know I am not the only Billy-no-mates out there!