Shoulder pain on my very first long distance tour
I went from daily rides of no more than an hour or two to biking every day for 8 hours with no training in between. My trap muscles in my left shoulder started hurting the second day in. It's now the 7th day and over 170 miles in and my shoulder still hurts in the same place/way after long rides. I gave myself 3 days rest in between the 2nd day and the next ride. I do about 50 km or 30 miles per day. No amount of resting seems to rid me of the sharp pain which occurs most frequently when going downhill. I raised the handlebars and adjusted the seat then went riding for about an hour. the pain returned. I don't know if I should keep on or give up and go hitchhiking instead. Thoughts/experiences?
More details:
I am riding a hybrid diamondback hybrid road bike. The top bar of the frame forms a "v" with the seat post, which is raised high for full leg extension. The handlebars are a straight bar.. My tour is planned to go another 4 months. I've always had to switch hand positions on the handlebars to stay comfortable on this bike which didn't seem like a problem until the ache started. Now I'm seeing everything and anything as a potential problem.