In my personal experience, I did horrible on the GRE and still got into my top choice school. It was a last minute decision to take the GRE so I didn't study and took it sick. I got a 145 Quantitative, 142 Verbal, and a 4 writing score. I also applied to only 4 schools and had a 3.9 GPA and was super nervous about my GRE score but thankfully things worked out and I didn't have to retake it. I feel like schools look more seriously at your GPA and personal essays more than your GRE, so if you did bad I don't think it will ruin your chances but a better score wouldn't hurt!