CRNA. Osteopathic programs (DO) have the same curriculum as Allopathic programs (MD) with the addition of about 20 more credit hours (these are kind of like a chiropractic education). Medical school requires calculus, calculus based physics for 2 semesters, organic Chemistry with labs for 2 semesters and a 300 level statistics class. So you do all this and pass the MCAT, get into a program. From there you'll do 2 years of coursework (sit for usmle 1) and 2 years of hospital clinical work (sit for usmle 2). But it doesn't end there! After graduating you apply for a residency. Nobody wants primary care or internal medicine and if you are a US grad you'll probably want a R.O.A.D (radiology, ophthalmology, anesthesiology, dermatology) - these are the sought after residencies. Regardless of what residency you chose, these are a minimum of 3 years (I believe the family practice is actually 4 now). A lot of states will let you practice with just one year of residency in any specialty, but no hospitals will allow you to practice until you are 'board certified' which requires completing the entire residency or even grant you hospital privileges. Liability insurers require hospital privileges to perform in-office procedures with the potential of an emergency (vascular ablation, lasik, eyelid surgery, tumor removal) so completing a full residency isn't really an option. So a year and a half for medical school prereqs, 4 years in medical school, 3-4 years of working 80 hours a week for $40,000 a year with $200,000 in student loans.
A RN to MSN program for 3 years and $45,000 in debt with a starting salary of $140,000/year.
I would only do the medical school route if you plan on going into the high paying specialties. To go into primary care and make $20,000 more a year than a NP after all that work would make me really salty tbh
If I were you I'd definitely do the CRNA route