Hello, I have studied your case. I will advise you clinical examination and accordingly investigation like MRI cervical spine or shoulder will help. Brachial plexus injury can be treated surgically if no relief with medication. For these symptoms neurotropic medication like pregabalin can be added consulting your doctor. Till time, avoid lifting weights. You can consult physiotherapist for help. Physiotherapy like ultrasound and interferential therapy will give you relief. I will advise to check your vit B12 and vit D3 level as low levels can cause increased muscle and nerve damage. Hope this answers your query. If you have additional questions or follow up queries then please do not hesitate in writing to us. I will be happy to answer your queries. Wishing you good health. Take care.