Do the cat/cow stretch. Get on all fours, with your arms straight and your hands directly under your shoulders; your knees hip-width apart.

Dear Respected I have gone through your problems. Rule.out acidity or medical issue For more clear advice I need to examine you in details along with some investigation like x ray and blood test. Revert back with all these. Regards Ortho Joints Dr Ssunil Dewangan

Greetings,  sorry about the pain.  Not to be worried.  It is not a disease nor any damage to organs, but just the ligament attachment at around chest bone and   ribs are strained causing pain. This all indicates your abdominal muscles and shoulder muscles are weak.  Your pain may also increase when turning in bed which all indicates it is due to poor muscle coordination between structures around chest.

Do u have any gastric problem it may be due to gas u may feel u comfortable to breathe and the pain will be over the chest too just have a cross consultation with a gastro since ur younger age nothing to worry about it do some deep breathing exercises which may be sometime helpful too