I know how you feel. I've been doing bodywork since 1973 and I really feel beat up sometimes. Plus I've had a back injury since I was 13 so I started out at a disadvantage. Sometimes I feel like I'm 100 years old and sometimes I'm sure I'll never make it that far.
Anyway I also suffered from tendonitis in my right elbow. It hurt so bad sometimes I couldn't use my right arm or hand. I thought it stemmed from my back problems so I asked a chiropractor about it. He said the only way it would heal was to quit using it. Hmmm, not a good option when you're right-handed to begin with, and have to work for a living. But he also told me to try taking huge doses of vitamin B-6, like 2 tablets 4 times a day and see if it would help. Then he said to taper off after awhile to 1 tablet 4 times a day, then just 2 a day, then 1. I asked him when I should start tapering off and he just said I would know. So I took 2 for 4 times a day for a couple of weeks or so, then started tapering off as he said. I was feeling better so I finally quit taking them completely. I did have a flair-up some time later so I bought another bottle and took them and now haven't been bothered for several years. How and why it helped I don't know and I don't know if it helps everybody but it doesn't cost much to try. My chiropractor sold me the first small bottle but told me I could buy it much cheaper at Wal-Mart. His brand did seem a little more effective so I asked about it and he said it had an ingrediant (and I don't remember what it was) that helped your body to utilize the B-6 better. You just had to take the Wal-Mart brand a little longer.
I saw your post and just thought I would throw this out there in case anyone would want to try it. It did help me but may not work for everyone. Doesn't cost much to try, though.
Dallas