I have e coli, &....?

Okay so I thought I had a kidney infection so when i went to the doctor i did a pee test and they said they werent sure so they sent it to the lab in the mean time they gave me some kidney infection medicine, when it came back from the lab they said it was E COLI. and they werent sure if the medicine they gave me killed it. so i took another pee test five days after the 1st appointment and i still had e coli. so now all they gave me is amoxocillin my mom didnt pick it up till two days after it was prescribed. i mean how serious is this. they dont even know how far along this is. it was just a normal doctor. not the hospital. so what is amoxocillin gonna do. i thought this stuff could kill me and they are actin like its no big deal. :/ he didnt test how far along it was or anything. i feel shaky and sick all the time. i almost p out a lot, and i threw up a few times but not that much. my apetite isnt really all that great. idk.