Breakdown during therapy

So most Saturdays I have to go to therapy for some and even though I have been going since I was 10, my parents still force me to go. Yes that doesn't seem much of an issue it's just going somewhere, but today I was really struggling and didn't really wish to go. My hypermobility was so bad I could hardly stand up, and as for two weeks I've had assessment piled ontop of assessment as well as it being the end of term it's been really stressful and my asd has just gone haywire - as a conclusion most nights this week have spent me crying basically. However I was still expected to be at therapy. I nearly cried on the way there and was the last out of the car because I thought that if I calmed down it would be okay, and it was for a bit. If you've never been to a therpay like mine it's basically animal care, and the people there are really sweet but it's just gotten so busy on a Saturday I've just been left out. Also the number of people is just overwhelming yet I feel guilty for asking not to go because well, I don't want to leave the owner of the place behind because she's so kind. Then I had the breakdown and I was just glued to the spot, all eyes were on me and my parents just didn't help. I think I was embarrassing them which just made it worse, but then the people just dissipated as the owner made my stepdad (who, I'm gonna be honest isn't a very nice person in private) help the other people feed the alpacas up top. The woman, we'll call her Mary, comforted me in an embrace (she's like a grandmother to me) as she tried to find the source of my tears and suddenly my mom was being really nice. After a bit I just couldn't do anything. I was in pain and struggling so much I had to go home, so I did. My little brother (9) accused me of faking because I wasn't crying in the car, but my mum defended me and I thought "Hey maybe it'll be fine, they won't yell at me" however panic started to set as we pulled into the driveway. And rightfully so. As soon as I sat down I started getting accused left right and centre, being yelled at for "faking" just to get out of it. Now my mum is ticked off at me because I won't give a reason for not wanting to go to therapy anymore, and luckily my stepdad is at work but I'm scared of what will happen tomorrow.