Losing weight to have a healthy pregnancy

Hi all! I am severely overweight and although I know women overweight can conceive; we have not been preventing for about a year. Some months we "try harder" than others. The other day it hit me... maybe God is trying to tell me there are some other things I need to get a hold on before we conceive...My health! I am strongly considering going through a major health kick and getting healthy and fit. Yes, I want to lose it all so I know I have done all I can to become the healthiest me to carry our baby. Some people may think it's crazy to lose all the weight to just put some back on when ur pregnant but I want to hear from you... Am I crazy to want to do this?