As you are suffering from
diabetes, there is a possibility of Adhesive capsulitus ( Frozen shoulder) on both sides.. There is also a possibility of radicular pain in hands due to nerve compression at cervical spinal cord level.. Do you also have any tingling numbness in hands..
Next Steps
You need to start shoulder movement exercises, take analgesic tablet, physiotherapy can be started..
If still not relieved, plan to get x ray of shoulder/ Cervical spine or MRI if the problem is severe..
Health Tips
Avoid lifting heavy objects. If pain increases on doing exercise, avoid that as well..