I feel your pain. Literally. Here's my story in a nutshell. I broke my ankle snowboarding about 8 years ago. I went to emergency and the quack told me it was just a sprain. I went back a year later and he said it was still just sprained. I walked on this broken ankle for about 3 years until I finally snapped. I went to a clinic and told the doc what was going on - I'm in constant pain, I can't sleep properly because I can't get comfortable, I've gained about 40lbs because I can't do the things I like to do and I'm really starting to loose my mind. So, being the brilliant doc that he was, he sent me for an Xray. He told me it wasn't broken. I said, BS, if it's not broken than why does it hurt all the time, I want to see a specialist. After about a year of waiting, I finally got to see the specialist. He took xrays, and bone scans and cat scans. All of which confirmed that my ankle actually was broken. DUH. I had to wait about another year before surgery. All he could do was remove the bone fragments because it had been so long since the original injury. I finally had the surgery and I thought I was on my way to living a normal life again. Wrong. Within 2 weeks of surgery, I got a major infection in my ankle joint. It's literally the worst pain ever. Had to have another surgery to clean up the infection. All and all, my ankle is better than it was pre-surgery, but not much. I'm still in constant pain, still gaining weight and usually miserable because of it. I miss the things I love to do like snowboarding, skateboarding, hiking etc, etc, etc... but oh well, such is life. Now, here's where all of this "story in a nutshell" becomes relevant. Because of my situation I can't spend much time on a ladder. That means no installs above waist level. It also means that I can't spend all day on my feet (I can, but trust me, it hurts like hell) so I try to avoid that. The answer to my problem was being fortunate enough to find a highly skilled, freelance installer. I've basically given him all my installs. This works out great for me because not only am I in less pain, but I am in the office where I can be far more productive than if I'm on location. Don't get me wrong, if for some reason my foot had to be amputated, I would not miss it for even a second.
My point is, don't let this injury ruin your life, you just have to find a way to work around it. You can still do signs and graphics, just get somebody else to apply them for you. Pay them what they're worth, add some mark up for yourself and everybody wins.
Don't worry AutoFX, it will work itself out. You just have to be persistent.