Hey!
You can lose maybe 30 in that time, if you really work at it--and that would be great, wouldn't it?
You would probably need to exercise 5 times a week rather than 4, though.
"Eating really healthy" has to mean eating fewer calories than you burn--it's good to eat better, more nutritious food than junk foods, but you can gain weight with too much healthy food also.
Good luck! Look around 3FC for information on different plans--check out the "Diets" tab on the home page.
Jay