Hi monkey!! Congratulations on your engagement!
I think the best way to make sure you keep the weight off would be to set yourself smaller goals as I guess it becomes more manageable
take each day as it comes and all that...plus I think it'll help you stay motivated 
I've also heard that staying away from heavy foods such as MacDonalds would be better for you as that can make you feel bloated and uncomfortable - just a tip! 
Believe in yourself and you'll do it no problem!! GOOD LUCK xx