Problems with work / Advice about Universal Credit and PIP

Hello,

I know I have posted about work problems on here before but I need some advice after today.

So today I had a complete breakdown about going to work. It has been bad for a while but today was the worst. I ended up curled up on the bathroom floor crying and screaming for about 20 minutes. Once I finally got in the car (my wife was driving) I was shaking uncontrollably and babbling hysterically, saying the same sentances over and over again really fast. I was scratching my hair and hitting my head with my hand. 

We had to give up and turn home.

First of all I wanted to ask if anyone else has had experiences like this about going to work?

Secondly, if I leave my job because of mental health problems and autism will it affect Universal Credit? We currently have a claim as my wife only works part time, not sure if we would get more or less if I was out of work with stress

Thirdly, how does PIP payments work? A friend of my wifes told me about it today, not sure if I would be eligable but my anxiety is so bad I am at the point where I pyshically cannot go to work

(Bear in mind I am still waiting for my official autism diagnosis. I have been on the waiting list for that since September, not long I know)

Any help with any of this I would be really grateful for