BPD treatment not suited for autism

I have a diagnosis of EUPD/BPD and I have been recently diagnosed autistic (6 months ago). I started a treatment programme called "Therapeutic Community" with my local personality disorder service last week. This consists of 3 days a week at the unit for 12 months with a mixture of therapy which includes social therapy with the other 24 "members" (patients). Everyone joins in different stages, and the other members had already been in the programme for at least a few months. 

I was extremely anxious for the first week, I struggled to fit in and found most other members completely disregarded me and ignored me. I had a couple of shutdowns because of the way it's made me feel, but understand it will take more than a week to get into my new routine of going and it will take time to fit in with the other members.

During one of the meetings, they spoke about their "Away Day" which they had organised way before I joined, and they had organised for tomorrow (Tuesday). The away day is an activity away from the unit, and is something the members organise twice a year. Tomorrow, they have organised to go pottery painting. 

I have told the therapist that I'm not going to go as:

• It's not something I want to do and then have to pay to do
• It's too far for me and unsafe to get to on my moped (30 miles)
• It was too short notice for me
• I'm new to the group and still don't feel comfortable around other members as it's just been the first week

The therapist have said that it will be marked against me for 'non attendance', which if I have a certain level of non attendance, I get put onto a "Contract", which is pretty much a disciplinary  thing. 

This has caused me a lot of distress over the weekend and feel like I am being punished for something that has been sprung on me without much notice. Being newly diagnosed autistic, I am trying to figure out whether how my brain in processing all of this is because I am autistic. As the therapist will instead see it as me avoiding it because of anxieties caused by my personality disorder, rather than it being difficulties because of autism. The therapist made it clear they aren't trained in neurodiversity, they just have some understanding of it. 

Am I being unreasonable for not wanted to go? Should I force myself to go and then deal with the likely shutdown after? Is it fair that it's going to go against me?

Any views welcome. I suppose I'm looking for validation to, as I feel like I'm going crazy with the way this is making me feel, and whether it's valid to explain to the therapist that I am struggling because of being autistic, but I don't want to seem as using as autism as an excuse.