Work hard, save money, live cheap. There's no easy way around it.
But you've gotta do what you love. You can't spend 7+ years training and not be happy. EM pays in the middle range of medical specialties. More than primary care, on par with several of the IM and peds subspecialties, but nowhere near some of the surgical subspecialties. But for 3-4 years of training, it's quite good. But the key is - you've gotta do what you love. It's a lot easier to work hard doing something you enjoy, than grind it out day after day doing something you're not really into.
I'm in PSLF, but it works for me because I wanted to do academics anyway.
I don't think it's worth doing academics just for PSLF in EM. I could get rid of my loans much faster if I just worked a private job. Private jobs pay 30-40% more, on average. It's just that I, personally, wouldn't enjoy it as much and so for me it is worth it. . But there's more to life than $, and what you do should not be purely a financial decision.