Stiff Neck- Levator Scapula

Hi everyone
I've been suffering from stiff neck and tension type headache from last 6 months. This tightness is around my temples and forehead between brows and it comes from behind the ears. It all started after a hectic month. I worked for 11 hours straight on computer for 1 month in bad posture (Forward head posture). Also i went gym at that time and did heavy barbell shrugs which i think contributed to this issue. I also have a very bad sleeping posture(i've corrected it). Even after having hundreds of visits to therapists and having taken tonnes of nsaid's i still have stiffness and tension headache. Whenever i give heat to my neck, the stiffness gets reduced but comes back after some time. Doctors don't know about this problem, they just say don't sit in bad posture which i;m not doing it anymore. I've become very tensed due to this problem as this affects my vision(further confirming that its levator scapula ?? ), Can't say its blurred vision but its more like related to stiffness in neck as when stiffness goes, vision is clear. (Eye exams have been conducted and they're perfectly okay)
Now what i've done is that trying out different exercises, like stretching pec minor, stretching levator scapula(Which further increases stiffness), stretching lats.
Also what i notice is that whenever i do serratus anterior exercises, my stiffness is gone for like 2-3 minutes. Also if i wear the collar (neck support), it also decreases stiffness. However, what i'd like to tell is that this issue is not increasing anymore, every single day, the stiffness is less but its annoying and it comes back whenever i work long hours on computer.
I've put my xray and what doctor report says in this post.
Kindly look into it and advice me what to do
Thanks.
http://imgur.com/a/tBPXWhttp://imgur.com/a/wjSX4
Heres the link to images:-
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Imgur: The most awesome images on the Internet

I've had a patient that I worked on for some time with a very tight trap and levator scap on the right side. I've done injections, joint and muscle work with only temporary results. I eventually understood why I wasn't getting anywhere when he said it was tugging considerably to the right. I think the only reason his head wasn't sidebent to right was because of all the work I did. I finally became clear he had cervical dystonia and I have now botox'ed all the tight effected muscles. I had two other cases that appeared hopeless but had a slight right sidebend tattle-tailing their cervical dystonia. One is almost off his opioids since he has had botox shots. I'm not saying that is your problem but it might apply to one of your readers and they should take note.

Have you tried ultrasound? I use a Sonic relief home use ultrasound for stiff muscles and neck pain. The trick is to use it regularly - like 2-3 times per day for a week or so. The muscles really do relax.