First off, best of luck to you. I'd contact the IPAP Program Manager to explain your situation. There is a TIS waiver (link doesn't work) but I'm sure they could email you a copy or you could construct one based off any of the other waiver examples that have working links. (IPAP contact link below)
I can tell you that on the guard/reserve side, you have to be an active drilling member for a min of 1 year before applying and it is risky. The slots are limited and you would still require a TIS waiver. The guard DOES need PAs (probably the reserves too) but I don't think the grass is any more green/less competitive.
I left active duty with 10 years TIS because I wanted/want to become a PA. When I attempted to apply on AD at 9yrs, there was no TIS waiver and I was simply told I had no chance. Once out, I looked into the guard and the recommendation from the AMEDD Personnel Program Manager was not encouraging in any way. Fast forward 1 year, I'm now applying to civilian PA programs and intent to join the guard after I complete a program.
Getting out is an option but not a decision to take lightly. Two PROS are that you have the time to focus on finishing prereqs and building your healthcare experience, assuming you don't have any. The biggest CON is that you lose your paycheck so you have to be financially prepared. The GI Bill will only carry you so far but it is a big help. The other big CON is that transitioning can (not always) be a difficult process, especially when you are going from a role where the responsibility and risk is high to a life with almost no risk/responsibility as a undergrad student. This has been my experience but doesn't represent everyone else - you may be different.
Now that I've crushed your hopes and dreams, I'd say don't let anyone stop you. If they say no, find another route. Remember that knowing the right people DOES help so use the military network you have now. If you've exhausted all resources for getting into IPAP via active duty then consider another option.
Good luck brother!