Muscle from neck to shoulder on left side stiff\sore for 2 years. What can cause this?

So I work in IT and think it's my setup but I've also seen a chiropractor around the same time it started that used to manually crack my neck. I have persistent neck and shoulder stiffness. I think it also causing my anxiety from irritating nerves. I see another chiropractor who randomly is able to get rid of it all. She does these neck and shoulder pinches (not sure what they are called) and I feel great for a few days. At most a week. Then it comes back.

My family dr referred me to a physiotherapist. It didn't work. Not sure if it was just a misunderstanding on their end but I didn't feel any relief. Now my family dr wants to refer me to a sports medicine dr and give me a MRI.

Any idea what it can be? I'm at a loss here since the soreness has been bothering me for a long time.