Hi,
I too can sympathise - I will share how I have coped with this over the years.
Firstly, I pull out of gossip or groups or whatever and I knuckle down and get my work done. I recognise that I am not there to make friends, but to work and I get down to my work and make SURE it is what is needed. There is no other way for me to feel good about work if I know I am missing something or making mistakes - it has to be of a high standard for me to feel satisfied.
Secondly, I take steps in my personal life to be fit for work. I HAVE to work as there is no one who will take care of me, therefore I HAVE to be successful at work and fit for work, and that means getting and keeping myself together, early nights, prep etc.
Finally, I recognise that the world of work brings me into contact with all sorts of people I might not otherwise be around - some of them are great and become friends, but some of them are not my cup of tea at all and I have to be careful around them, and occasionally stand up for myself, which I have had to learn how to do.
In your shoes, I would journal about what I personally need to do, and then I would set about doing it. I would work quietly and calmly and be focussed, I would not talk, I would not involve myself with anything other than head down, solid work - and get results, and then you can relax knowing you are on top of things.
I would also do things at night to calm myself and would probably use positive affirmations like 'I am safe and doing well.'
I would give it some time with people, time where they experience you being quiet, focussed and delivering solidly for the team - they will soon come around xx