Ok, that's a start. I'm almost positive this will be impossible to pull off due to scheduling issues, but if you can do 3 math classes a semester the pre-requs can be done in a year. Here is a huge warning: advanced mathematics call for a different level of quantitative reasoning than elementary math. Some people are good at "computational" math, but fizzle out when things start getting abstract.
Be aware that 95% of the admitted students were engineering, math, science and highly quantitative finance majors. I don't know where that puts you, but if your going to devote your time to mathematics, do it for the math, not for MFE.