How badly do you want to be a doc? What’s your alternative career path if you withdraw your acceptance?
If you have other skills that lead to a good paying job, I would go down that route. Could you become a PA? Shorter schooling and still get a decent wage. You will have enough money to help out with family, and enough time to start your own family (less schooling. i don’t know what the debt situation is for PA school though).
You’re definitely in a tough situation. I know many will tell you to bank on HPSP, committing to primary care, etc., but I just feel some type of way about making a commitment before you even do clinical rotations.
Good luck with whatever decision you make.