What I mean is that you've learned so much by yourself or elsewhere that the teachers think you're too advanced for a level 1 class but you would start at level 2 and start getting qualifications from there. Or do you think it's worth it to get a level 1 as well?
For example, when I did french evening classes, I learned enough French by myself to go straight to intermediate/gsce classes and not start at the beginner ones.
I'm in a very similar boat to you. I also have some issues with hearing/auditory processing as well but because I'm autistic and have panic disorder I can often get non-verbal when overwhelmed and it's happened during uni before, even, and it was really hard to deal with. Compared to other languages I've studied, BSL has not been that hard to learn for me.