What`s going on ?! I`m very scared ! !?

recently , i went to the doctors to have a check up . and just being curious i asked for a vaginal inspection to see if i have an STD or a yeast infection . all of the above was denied . so about yesterday , i had oral intercourse with a boyfriend , and he brought his head up and said that i`m kind of bitter . and i was like is it horrible , and he shook his head and said it was manageable . so i tasted it , and it was kind of like a tart , tangy taste . and i didn`t think it was "manageable" . i have little tiny pebbles of cottage cheese looking cream coming out of me , but i am due for a period early next week . i heard this was normal from other women . but i`m young . . . i have worn jeans in so long , due to the school break , but i`m just making sure everything is okay . i don`t have a strong odor to my knowledge , and when i take showers i don`t wipe any discharge when i`m drying off . i have no itchin , unless i`m shaving . and i`m not burning at all . sometimes the pebbles are there , sometimes it`s not . it reappears right after my period ends also ! and when i have oral performances , sometimes i have a patch of white stuff on my panties . i`m very scared , please help me .