I know youre eager, but I wouldnt do a gap year. Youll thank yourself when you graduate. I started flying at the end of my second year of my degree (biology) and will be entering my fourth and last year in September. Ive logged 75 hours so far just by flying on weekends at my own convenience. If you only flew 2 of 3 hours a month over the course of your studies, you could easily graduate with a ppl, however Im not sure what your financial situation is.
If you really want to fly you probably wont want to be in school like me so its good to get it out of the way as soon as possible. I can see myself wanting take a gap year too if I wanted to be a pilot in highschool, but Im quite pleased how things have progressed for me thus far.