Welcome to the forum Shazza. I also have an auto-immune illness, and I get ESA. It's not so much about what illness/disability you have, but more about what you can do because of your illness/disability.
If you follow our guides (there are links in my signature below) and slowly work your way through, maybe with help, you'll get there. Have a look through the forum too, to get more advice from other people. The main things are:-
- Get supporting evidence from your GP and any other medical person you're involved with.
- Never send originals to the DWP; send copies and keep originals.
- Never phone the DWP, always put everything in writing.
- Post paperwork by Signed For Recorded.