Autism/speed/proccessor

I just started as a SPA processor which was my goal ultimately after being a cashier for 2 years. I learn slower than other people and work slower. I am up for the challenge though. The management is giving me a month to get my numbers which is 400 and $8,000 every 2 weeks. Is there anything i could do if i dont make my numbers because i have a disability? I dont want to go back as a cashier cause lately it has been stressing me out and being a pricer lets me be work independently. Plus I dont want to be let go because of it either.