Left shoulder and neck pain. Guide me.

Hi, I have  pains in both my shoulders( sometimes left and sometimes right) and also neck intermittently. Last year I developed serious pain in my right part while playing badminton. It got better with medications and few physio therapy session. But i believe its not sorted. The pain on shoulder can be felt while carrying my office bag and also it feels weak sometimes. There have also been 2/3 times when I woke up in the middle of  night with a sudden unbearable pain on my left shoulder. After   a lot of struggle, I manage to sleep and when i get up in the morning the pain vanishes. Maybe it has to do with wrong sleeping position but it never used to happen before. Currently i am having pain on the left shoulder and left part of neck. Please guide me.