desk chair with wheels (Welwyn/Luton/Hitchin/Harpenden)

In trying to my uni work at a desk with a stool, unfortunately due to previous back injury this is excruciating. I can’t use the couch in the living room as we have 5 cats that feel the need to help me study!!
I work full time but I’m doing a degree apprenticeship to the university to qualify as a nurse. I’m absolutely desperate please please if anyone has one going spare you’re amazing