Rogaine is pretty well useless except for some very specific types of hair loss. Propecia works and it's shown to be 90% effective.

I think the rapid weight loss has caused your testosterone levels to go up because fat changes testosterone into estrogen. With the loss of fat you have a much higher testosterone now and so you are seeing the hair loss. Propecia prevents the conversion of testostereone into a form that causes hair loss.

Oh yeah, you can get a presciption for proscar, the prostate medication. It's just propecia at 5x the dose for the same cost (can you spell drug rip off?). So you cut the pills in quarters and save tons of cash.