I have been pretty much idle for around 10 years, I have started my comeback 6 weeks ago.Everything has been fine until this last week, my endurance has taken a nose dive and I have lost some on my range. I am playing on a schilke 16c2 and thinking of going to 16b4. I was up to about 4 hrs a day with long breaks between each 20 min session. I know this will take sometime, I am 52 and don't expect a whole lot right off, but I have hit a major wall, my sound is great, but I am worried I might have hurt something. Is losing endurance and range common at this stage?