Job title change in work for 20% extra role

Hi,

I was wondering if there was any help that can be done in the situation I am in. I have autism which my company is aware of, my job made employees redundant and later on I had to sign a title change as this would only be 20% more workload but this includes doing not only my role but also the role the employees were made redundant for. After changing title and redundancies made my job has turned out to be over double what was said and not the job I signed up for. Is there anything I can do other than finding a new job?