Struggling with Physical and Mental Health Conditions While Working

Please if anyone has any advice I would be grateful. I am really struggling to stay working because I have physical and mental health conditions. I had an interview this week and have a second one next week for the same job and I’m feeling too anxious to continue but I need to work. I don’t know what to do, as it’s a physical job too so I’d be in a lot of pain. I haven’t told them about my disabilities incase it stops me from getting the job. Do I just suffer the pain and anxiety or look for a sitting job that would cause a lot of anxiety still and stress. I don’t see a good option.