Introduce myself, feeling sad

I'm in my 50s  have a adult daughter and pet cats.

I have health problems as well. I.find it extremely difficult to make friends and understand people. I.end up getting hurt and I retreat .At the moment I am very unhappy.  I used to have who I thought was a friend who had a go at me for trival thing. I said I needed.space for a bit. And because I wasn't messaging her for a few days , she accused me of snubbing her. 

Then she said vile things about my counselling I was having and accused me of being fickle and saying horrible things. I used to go to a craft group but can't now as she goes and turned another against me. This upset me. Stupidly I post it on Facebook and said how one sided the friendship was. It was true. Her moaning about her life etc. Anyway someone saw it ,had a go at me .I took it down and apologise.  

However someone's sent her my post and she put a letter through my door. Being horrible and saying I don't have autism,  I play on it, . I have been diagnosed.  She said I must of managed all this time , I was diagnosed in my 50s. I have struggled all my life. Then she said she is going to sue me for slander. . I am terrified.  Felt like ending it all. 

 Didn't put lies, why is that needing space so bad.