Two quick points: First, you have plenty of control over how hard you go in workouts. No one, including your coach, can see inside your mind to discover whether you're at 7/10 or 9.5/10 on the intensity meter. Run the workouts at an intensity that will allow you to stay healthy, and adjust your mileage appropriately too. If you're as motivated and self-aware as you claim, it won't be a problem to resist the external pressure (from coach and teammates) to race workouts.
Second: your story is very, very familiar. Thousands of kids go through this every year -- especially smart kids who like to analyze what they're doing. That being said, for a whole bunch of different reasons, quitting the team almost never results in a positive outcome. (Sure, you trained yourself in HS and had success -- during a time when your body was developing so rapidly that you would have gotten faster even if you didn't train at all. Suffice to say that it's easy to do that for a year or two, and very hard to maintain.)
I was certainly one of those kids -- I came from a fantastic high school program and went to a university with an ex-sprint coach who was a complete moron. I got 15 seconds slower over 1500m in my first year, which made me resist his training and half-ass his workouts in second year, which made me even worse. I didn't quit the team for the same reasons you don't want to (teammates), and in third year, I decided that it would be better to go 100% on a crappy training regimen than constantly half-ass it trying to alter it to something I thought was more appropriate. To my complete surprise, I ran 3:44 that spring, a 17-second PR.
That didn't change my opinion of my coach, or of his crappy training program. But it taught me something I still believe strongly: the precise details of workouts are a very minor component of running success. Working hard (which you can control), staying healthy (which you can control) and attitude (which you can control) are the keys.