Suggest Treatment For Cystitis

Hey Im Sara ,

I am 17 , 5 ft 4 and about 149 lbs

I Have been with my partner for about a month now , and about 3 weaks ago we started to have sex , Since i have had Cystitis Which i treated myself by drinking lots of water ,it went away after about 4 days

However i visited my doctor a few days after as i was extremley tired and actually fainted outside of work , I stayed on the floor for about 2 hours and then felt well enough to walk home .Which i did as soon as i got home i slept again for a whole week , I didnt have the energy to walk around much .. Anyway the doctor started asking me questions so i told her about the cystitus , and she had me do a urine test Turns out i hada bladder infection and she gave me tablets to take twice a day and told me it will hopefully be better in a weeks time , Its now been two weeks and my cystitis is back .. I am not as tired however .. Another thing is that everytime i have sex ; i bleed , Either during and after however it only lasts for about 3 hours and then its fine again until we have intercourse and then t starts up again .. I have also noticed that its starting to smell , I have never had the smell before , its not very plesent .. Although this may not have anything to do with it i have also had 3 periods this month ...

Could there be a tear? is it his fault? Please help :) x