I feel so selfish when my mum is going through worse

For context, my mum has had Parkinson's for 20+ years. She got it when she was super young (39 y/o). She has had deep brain simulation 10 years ago which has helped her tremors but anyway she is the strongest person I know. She's full of life and happy, even tho now she's in a wheelchair. She hardly complains and is a joy to everyone around her. She would give her everything to her children. I have a very good relationship with her, I got married and moved a bit far from her but I try and see her every weekend. She lives with my dad who looks after her 24/7. Recently I've developed a scalp condition and I've been so consumed by own problem, which is made worse by my OCD and feeling contaminated. I'm going to therapy but I complain to my mum so much and I'm really trying not to but I feel like the worst daughter ever, and I'm scared I'm going to lose whilst worrying about my stupid problem.

I feel selfish and stupid. I'm trying not to focus on my problem but it's making me feel so dirty. I want to focus on my mum and making her life better.