With soft tissue damage, the muscles get pulled and then the other muscles can pull the backbone crooked and it can caused pinched nerves which further cause muscles to go out of whack. This can effect the shoulders and arm signals to the muscles and cause pain all over the body.
It would be way to early to go to the chiropractor, but maybe later it might be an option after things have settled down. Right now you need something to relax the muscles. I used to get Flexeril from the doctors, I actually used those many times and for my back pains they worked pretty well. Not many side effects but the generic ones didn't seem to work as well. Something in the inert ingredients must have made them work better. Adjuvant chemistry is patent protected and does not have to be listed and other companies cannot add that in generic drugs.
I don't know which is worse, Valium or flexeril. When you have to work Valium might actually be more of a problem with making dumb mistakes. Flexeril is probably a lot more expensive though.
Later on maybe going to a chiropractor might be a good idea, find one who is gentle though. No bone breakers, some have activators to gently push bones back in line. Stay away from the kind that twists you all over the place, the first chiropractor I went to was one of those and he fixed my back then took it back out again.
The chiropractor I went to was a doctor, he worked at the University of Michigan for a while before moving here and he was good at what he did and was not too invasive. I never walked out of his office worse than I went in, he also was not one of those that would keep you coming back for months, maybe three appointments or a few more if he was trying to straighten out something. He was very honest and wasn't someone who was greedy or a deceiver. That is rare when searching for a chiropractor.