Smell down there ? :/ *girls only, tmi*?

okay. well im fifteen years old and in the ninth grade, if that means anything. ive never noticed any "smelly" discharge until i hit the 8th grade, or around that time. i'm a very clean person, and i don't know what im doing wrong. i wear deodarant, i bring it in my purse and put it on a lot, so i know its not that which smells. people have said "you smell like fish" or "you smell like ****". my family say i do not smell, but i feel completely otherwise. when im home, i feel "free" and do actually notice less smell, odd right? but if i go to school i bring alot, like 11, pantyliners in my purse and change them EVERY period. for the past couple of days, though, ive been bringing an extra pair of underwear to school and only about 5 liners. if i dont wear the liners, my underwear smell, i cant even describe the smell. its not fishy, though. its not "normal" either, and i know that for a fact because it hadnt started until a little bit ago, the 8th grade. i do have anxiety, which does make me sweat more, probably down there too. i wipe MORE then i have to, but i still am always so "moist" down there, ugh sorry tmi :( lol. i shave EVERYDAY down there, everywhere actually (underarms, private area, legs). im not hairy at all either, i just do. oh and ive noticed that i get realllly bad gas in school, like gy feelings in my stomach, that tell you you have to fart. i "hold" it in and like dont fart, but for some reason i feel like i still am. gosh. its so annoying and im getting sick of it. what the hell am i doing wrong? what do i need to do? oh also, i also get "yellow" stains in my underwear, which smells THE WORST. i dont even have to directly smell the pantyliner or my underwear, cause i dont, ew, lol, but i just get a whiff of it when i pull down my underwear, that kinda thing. im really sorry if this is tmi. thanks in advance everybody!!(: