I've found that you usually can't exercise away these kinds of pain..

You might have some trigger points in those muscles, and they need to be resolved before anything else will help.

A tennis ball , dog ball, anything somewhat round and that you can use to apply pressure, or a friends thumb or knuckle..

I used the ball against walls , cabinets & on the floor when at home, but sometimes you need a person to get a specific spot that are hard to reach.
And you have to get all of them as some of the latent ones will activate after the major ones are resolved..
http://neurotalk.psychcentral.com/thread125577.html

Unfortunately working may be re triggering those as soon as you get them resolved.. It is very hard to see benefits of PT or self care when working.

Have you read about the spoon theory ?
It is like a bank account of uses.
The PT and selfcare adds back $$ , but activities take away $$.
So working a full day will put you in neg $$ and all the PT & care cannot gain enough as the next day of work subtracts more again..

If at all possible modify your work as much as you can to be less draining.
I went right home for months and did nothing but ice and gentle stretches..and it still didn't get me ahead of the negative $$...

I banked as much of my real paycheck as I could because i knew I wasn't going to be able to maintain working much longer at that time.

If you can get some expert PT and/or a multi modality chiropractor, I think it will be beneficial for you.
You need pain relieving modalities not exercises..IMO
Like ultrasound, manual TrP, low level laser, IF stim- that sot of stuff first...

some of these might be helpful for at home- getting the shoulders back gently -
http://neurotalk.psychcentral.com/album.php?albumid=422