It is a mystery to me why the GRE is a thing. It tests basic but general knowledge. If I were evaluating a potential grad entrant, I don't think I could glean anything from a good score, although I guess I may be able to glean something from a bad score.
GRE notwithstanding, I think public health is only going to be a growth area. You should find a place that is in need of grad students, then you can probably get a research or teaching job and scrape by on a stipend but at least no debt. It will be well worth the effort of looking even if you come up empty.