I've been with my PI for over a year now and I can see that he really dislikes my work not matter how hard I try. I've had him as a professor in about 3 classes now, but I barely spoke in class. I tried to get a LOR from him last year for a summer program, but he refused to write it because he wasn't confident I could handle it. I recently went back to him and he said he'll take me back, but with hesitation. I believe if I ask him for a LOR for med school, I believe it will just bring up the negative qualities about me. Should I switch to another lab or could I just not submit a LOR from him? I hear that I am required b/c it'll send up red flags to the adcoms...