My fondant was fine then after i started decorating i noticed the fondant was getting stretch marks on one side then a huge! bubble formed...and i feel like crying now. I put a small pin hole in the bubble hopping it would go down, but not luck and i tried to move the air towards the pin hole but that seemed to make it worse. I need some help
Was your cake cold or frozen when you iced it? As a cake warms up the air inside it expands and if it can't escape the fondant will bubble, this can also happen as a cake settles after stacking due to the additional weight compressing the crumb. If the pin trick didn't work or your fondant has lost its elasticity and won't smooth back down you may be best just to recover your cake now it's at room temperature.
There are loads of threads on CC about fondant bubbles, you should be able to research many of the causes to stop it happening again :)
If your fondant hasn't lost it's elasticity try sticking a straw in the cake and sucking the air out. Then smooth and repair the hole with buttercream or royal. Lips do not touch the cake.