have they mentioned you might have bursitis/tendonitis??
I had that for a VERY long time.. I used to work on a job where I had to use the computer. ALL that repetitive movement adds up...e.g. reaching for the mouse (if it's at the side of the computer) typing all day , reaching to either side of you .. basically anything where you body is not completely in line..
I had them fix my work station so it was ergonomic friendly and even got a different mouse that at the time was a roll ball so that I was no longer clicking.. and none of this really worked. I did rehab and they also gave me muscle relaxers.. (seems to me they treat everyone the same way) and I wasn't into taking a bunch of pills..
what really worked.. MASSAGE........ and more massage and then you have to get up from your desk and stretch your entire body.. not just your neck... the nerves run up and down your body, so it's important to release ALL the tension... also, a heating pad can be good but make matters WORSE.... you see, warmth opens up the capillaries and allows for more blood flow to get to an area but IF you already have inflammation, then too much warmth can be a detriment in that you are allowing even more pressure to the area. I was told NOT to use the heating pad all the time..
additionally, I eventually had to leave that job.. because although I would take measures to avoid the pain.. working so many hours on a computer just wasn't helping matters..
you may not want or be able to leave the job. so it's important now as a younger person that you nip this in the bud...... because as you age, your tendons get more stiff and hence, tendonits can get worse.. think of them as rubber bands... right now, they are all rubbery and bounce back ... when older, they can be more like one of those older rubber bands that lose their shape...
usually unless it's a doctor that deals SPECIFICALLY with repetitive injuries.. then most just want to give you pills.. that is what happened to me at first.. see if you can see a specialist and they can help you get to the bottom of this..
best of luck