Any advice on being kind to myself when my disability is most likely my own fault?

So, in essence, I suffer from really bad leg pain, which most likely comes from years of poor diet and little to no exercise. It's hard for me to be willing to allow myself to look for accomodations when I caused my situation to begin with. All online resources seem to reassure people that their disability isn't their fault, but it's not very comforting to me when I'm almost 100% sure that it is my fault. Any advice would be appreciated