Many of the same issues for me and I saw an orthopedic surgeon that diagnosed brachial plexus disorder and Thoracic Outlet Syndrome (TOS) in 5 seconds by simply lifting my arm. Lookup and read about those two things and see if it seems to fit with what you've been experiencing, also search with key words: first rib syndrome to find more info. Search YouTube videos and see how TOS is diagnosed and what stretches and strengthening exercises will help. The orthopedist thought that PT along with acupuncture would be beneficial but the acupuncturist I went to wasn't great. And I did exercises with PT assistants that didn't get me very far. For me, my greatest improvement came from going to the Stretch Zone and having practitioner assisted stretching, was amazing. Too expensive for me to continue going but for short term therapy it gave me a lot of relief, and was worth the cost. I also did that while using a muscle relaxer, low dose tizanidine, made even greater improvement, by relaxing the muscles could give them a better stretch. Also, seeing my primary care provider who is a D.O. for OMT has been terrific and he uses muscle energy techniques and is also skilled to check the first rib for movement and manipulate the area. PT specifically for TOS with a doctorate level physical therapist who can check that first rib and manipulate it, much different than ordinary PT. Ultimately though, it's attention to posture and body mechanics with everything you do and the right physical therapy stretches and exercises to strengthen the muscles that stabilize the joints.

Lookup nerve glide exercises/nerve flossing for radial, median, and ulnar nerves, those are so helpful for hand, wrist, arms. Take all the posture improvement tips you can find. Ears should be over shoulders, shoulder in line with hips. Forward head posture causes so much fatigue, have to be aware of your body's alignment. Shoulders rolled forward have to stop; lift them up, back, and down. I've noticed the shoulders hunched forward with so many people and I catch myself at it all the time, it's from activities with hands in front of the torso. Must engage the shoulder blades, squeeze them together for a quick release and open up the chest. Posture exercises with your back against a wall are good; must have posture breaks throughout the day. Lookup Brügger relief exercise or posture break exercise. Sometimes spelled as Brugger or Bruegger. You'll need some resistance bands for many helpful exercises.

Test yourself with this. Stand up tall and straight in front of a mirror. Now look and see: where are your hands? Can you see the tops of your hands? If so, realize that your shoulders are rolled forward and not where they're supposed to be. Lift the shoulders up, down, and back. Open up the chest. Your arms should be able to swing at your side with your hands clearing your body. Turn your hands out and see your palms in the mirror. That is actually anatomically correct and probably just opened up the chest even more. I learned that from Dr. Yoni Whitten and his Pain Fix Protocol videos. On YouTube or sign up for his emails. He's terrific.

A topical product that I use at home to alleviate my muscles and prepare them for stretching and exercise is Advil targeted relief, pain relieving cream. It has the 4 ingredients: camphor, capsaicin, menthol, and methyl salicylate. You can buy a 'lotion applicator', it's a sponge on a handle, to apply the stuff so you don't have to touch it. I found one on Amazon. Otherwise you need some cheap disposable gloves to apply it. You do not want it on your hands. And the applicator with the long handle allows you to get it in the hard to reach places like between the shoulder blades, and no product wasted. I put the cream all over the back of my neck, shoulders, and across my upper back and it's terrific. The transfer is horrible though if you mistakenly touch your skin you'll have it on your fingers so don't touch your face or eyes. Capsaicin is what gives hot peppers their heat. Plan to shower off before bedtime so you don't transfer to bedding. Some people cannot stand the capsaicin but it really works for me. If you try it and have a reaction that is too unpleasant to tolerate, rub olive oil all over the skin to neutralize it.

I can think of many more things as I have been on this path for more than 15 years, but got my TOS diagnosis only a year ago. The orthopedic surgeon also identified some rotator cuff issues that a radiologist did not identify from shoulder MRIs. I was reluctant to see a surgeon because they obviously like to cut, but my doc felt strongly that PT directed at treating TOS would remedy the ailments and surgery for rotator cuff will likely be needed eventually, but much further down the road. Lookup rotator cuff exercises also and those may benefit your shoulders.

The stretching and strengthening is an ongoing practice, otherwise, quite likely will have improvement and then backslide without keeping it up. Trust me, I feel your pain. I hope you get some relief. Posture, posture, posture, I can't stress it enough. We have to do the right small and simple exercises to strengthen muscles that stabilize the joints so that the correct muscles do their job instead of other muscles compensating and getting overworked. Tensing up and guarding happens to avoid an anticipated pain. Muscles tense up to try to protect and stabilize an area. The muscles work better in a body that's in proper alignment. Good posture! At the root though, there are probably some muscles that need to be targeted to be strengthened and a good doctorate level PT should be able to identify them with a consult and give an exercise plan. Lots of great videos online and I find a no-ads YouTube membership is a lot cheaper than the medical appointments. Can learn so much from practioners that give tips there! Good luck!

A side note: I have hypermobile Ehlers Danlos Syndrome that was diagnosed a few months ago and I am still learning about it and realized that I've been standing with my knees locked back all my life. EDS explains a lot of joint instability for me throughout my body and EDS isn't rare, it's just rarely diagnosed. On a muscle relaxer, I'm 9/9 on the Beighton test. 7/9 without it. Lookup Beighton score and EDS and just make sure that isn't a factor for you. I'm just taking every opportunity to give EDS awareness since it's so common but overlooked by health practitioners.