Please help? I'm new and I'm at a loss as to what to do.

Hi.
I'm nor sure how this works..but I'll try. I am on Social Security. I have been diagnosed with major depression, extreme social anxiety and PTSD. and on medication. I spent the last 3 or more years totally reclusive and my stress level in nil. I was near agorophobic and to be around people is near impossible. It seemed the only way I could be calm was to be solitary/a hermit...Tv, radio, music in department stores were like chalk on a blackboard. My CNS is shot. About a year ago, my first love/first marriage came on the scene. I have tried to explain my illness. I can not be gainfully employed...I am NOT the "can do" kind of chick he married many years ago. However, he, nor anyone else in my family understand at all. I tire easily....They expect me to work like a trooper, socialize as in the old days, and when someone shows up unexpectedly at my door...it's like some one has hit me with an electric shock and i begin to cry. The worst ..the real worst of it all is, although I have told, explained and pleased to NOT put very much stress on me....They do anyway...as a result I "go off" yelling at everyone. It makes me feel so terrible, The guilt is the worst of all. I am desperately trying to force myself to heal..but as a result I'm labeled a witch who yells at everyone. I;m heartbroken..and I don't want to go back into my reclusive world..but, look what's happened...When I was alone...no one was in my world but me...by coming out...I've succeeded in only humiliating and embarrassing myself as well as the guilt. When my threshold is maxed out for stress..that's when I start arguing and yelling. What can I do to stop this? Has anyone else with PTSD ever yelled at those you love? Is there any hope/? Thank you