What do I do? College now with post 9/11 gi bill or wait 1.5 years?

I’m in the navy as a Hospital corpsman and I want to become a PA. I’d loved to go the officer route rather then a Civilian PA. The navy recently made a new rule about tuition assistance were you have to wait 2 years after enlisting to get the tuition assistance so that’s roughly a year and a half left until I can use it. I really want to start picking away at college classes but I cant without tuition assistance unless I use my GI bill. I also plan on re-enlisting up until I can go to PA school. Preferably I would like to get my bachelors in pre-Med while I’m in and then try to get into the enlisted to officer program to become a PA but I’m pretty sure I have to be a e-5 (and I’m an e-1) so that will take years. I also can’t go to school full time, so that “4 years” to get my bachelors with be longer which is why I want to start right away. At this rate I won’t be able to go to PA school until I’m in my early to mid 30’s. So what would y’all do? Wait the year and a half to go to college or start using the GI bill?