Greetings,
Sorry about your pain. poor posture contribute to should pain and the diagnosis of migraine is also related to poor posture.
Next Steps
If you can find a physio who can correct your posture will cure both shoulder and migraine problem. Alternatively if you want to cure your problem on your own. then you can do exercises. just mail me your mail id. will guide you through the process.
Health Tips
Dietary modifications also plays a role in shoulder pain and migraine treatment. Check
vitamin D3 level and let me know will plan a diet program to proceed further.
Remember, do not be in pursuit of just treating pain, find the cause of what caused your pain and this approach will give you permanent cure. So ultimately your cause is poor posture and altered dietary pattern.