STOPPING PEP???

i was put on PEP because a condom broke. the man said he tested negative for everything 2 months ago but the DR said i should start PEP. im 18 Days in and the side effects are unbareable. I am so weak. I can hardly stay awake. The nausea is overwhelming. I feel lightheaded. I went to the ER and they told me im fine and brushed it off. I really want to stop taking PEP. I feel my risk isnt that high to begin with.. ( i am female )