My constant "knots" are in my neck, shoulders, tops of arms, hips and back due to my chronic high level of anxiety - despite medications for my mental health issues. But that is not the only culprit. Of course I could list multiple suggestions/activities to reduce stress/anxiety but you already know them. Already mentioned is meditation (to detach) and daily exercise (walking?) not only for the body - but for the mind...increases those feel good endorphins.
Your particular "knot" condition sounds particularly alarming. In my humble opinion, mental health issues and obviously physical health issues all must be ruled out (one by one) to, hopefully, find a cause.
Having said that, I know for a fact, chronic high levels of cortisol/adrenaline in the body due to an unmanaged serious anxiety disorder can and does affect the "body" in more ways that I can tell you. Constant stress/anxiety is a killer and the root cause of so many physical diseases. The mind-body connection undeniable. Are you in therapy/see a psychiatrist? (I believe you most certainly should be). Do you have multiple layers of trauma in your life? Physically, possible other causes...are you on cholesterol-lowing medications? (could affect the body severely). Do you have an autoimmune disorder? Have you ever tried trigger point injections? (the effects are only short term). Have you seen a pain management specialist? Rheumatologist? (I would start here first in addition to mental health support). Think back to when this particular "knot" condition started years ago...can you identify a trigger? Even if "seemingly" small? Or was there a major change in your life? Happy or sad? Doesn't really matter IF it somehow affected your "mind"...what does your PCP say about your presentation? Helpful or not? You might want to do some real investigating...such as researching "rare" diseases. Maybe you are there? I would also consider, if you continue to be at a dead end with your ongoing pain condition, to call one of the 2 top medical clinics in the country.
The Mayo Clinic or The Cleveland Clinic. They both have pain management specialists/departments & located in different areas of the country.
Yes, it might be a huge inconvenience to travel there, expensive, referrals may be needed, etc. but at this point in your life it sounds like to me you have NO quality of life.
Do you wish to continue to live the rest of your life as it is now?
Only you can answer that. To me it's a no brainer.
I wish you all the very best in finding answers to your never-ending life of pain. Don't give up faith and hope.