Here as per your explanation looks like pain in between your shoulder could be due to
muscle weakness for the same place or it can be due to spinal curve loss at cervical level.
Again you also have pain for your Lowe back means either it can be spinal muscle weakness or loss of curve at lumbar level.
Along with this spinal pain if you have any thing like
numbness or
tingling sensation then it could be nerve compression at respected level with disc problem also. But if you have pain only at spinal level and there is no
radiating pain to hand or leg then it can be related to bone weakness, muscle weakness or there is some thing called as
ankylosing spondylitis.
How ever the conformation can be done only with MRI and
blood test for Ankylosing spondylitis.
As per the report you can visit orthopedic and plan for your treatment. For severe cases here he will suggest for surgical option and for mild issues he will suggest for
physiotherapy treatment with spinal exercises and few medications.
How ever even after after surgery also physiotherapy advice for posture and spinal exercises advice is very important so go ahead and follow it.
Along with this you can also use hot and cold pack at home for some more relief.
Headache also can be related with spinal problem and should improve along with this treatment.
Apart from this for your gastric issue it may or may not be related with this. In case if it is relates with your spinal health then that will also improve with spinal health. And if its not improving then I suggest to change your life style and diet habits tk healthy habits. And even after that if there is no result then you need to visit a specialist for this for proper evaluation and treatment.
Take care.