welcome,you are just now 15yrs& getting pain abdomen,bloating
indicates that,you your abdominal muscules are so,weak&whole abdomen looks like flacid belly, itself indicates that you are not exerscising at all. otherwise you might be running hormonal
,groth hormone. these dificiencieses will cause bloating,pain abdomen&even you may be dipressed as well.so get complete evaluation for thyroid gland,pitutary,stool examination is absolutely nesessary for you.hence, plz consult endocronologist&gastroentrologist &have good healthylife.