I did the diet for 7 months and it is really hard. Constantly worrying that you are putting the wrong thing in your mouth and will ruin your sway, stressing constantly and not being able to snack on something yummy that you really like, watching the clock all morning waiting to eat. And the worst thing is knowing you are spending so much money, time and stress on something that cannot guarantee to give you what you want. DS3 was a failed IG sway and it was horrid knowing it was for nothing.
But for me I was lucky and it worked, I am expecting a girl after 3 boys. I really hope it does for you, but even if it doesn't, you have done everything you possibly can to change the outcome, if you get a boy, you throw yourself into celebrating that he is healthy(hopefully) and celebrating the joy that 3 boys bring.