Welcome to HCM.
Your symptoms is suggestive of vitamin B12 deficiency
.Pain might be due to shoulder joint sprain
Go for certain investigations like cbc,b12,s.calcium,d3,uric acid.
Start nsaid with muscle relaxant
to subside pain.
Take therapeutic dose of oral or intra muscular vitamin B12.
Take calcium and d3 supplement.If not improved than go for shoulder joint x-ray.Physiotherapy
will be helpful.
Also go for ECG to rule out cardiac pain.
Consult physician for perfect diagnosis and better medical management.