I should also mention that 3/4th of it is already done (the part with the bedroom upstairs). However the remaining portion is open to the elements on the top. Now I already did the insulation by putting it between the 2x4's..so those are directly in contact with the inside portion of the roof. And then covered all with vapor barrier. But someone told me that this is all wrong and I will end up getting mold, and was supposed to lay out the drywall against the h-beams and then spray the insulation on top. Also that i have shut off air circulation between vent on the roof and portion right above the garage door where there are some gaps. So if i've messed up, should I be ripping of the vapor barrier, pull out the batts and then lay em down side by side once i put up the drywall?
Need some light on this...Thanks

Your post is very hard to follow, but if I understand it right, you have some mistakes. Your vapor retarder needs to be as close as possible to the space that's warm in winter, normally the living space unless you are somewhere in the very deep southern U.S. If you have insulated tight to the under side of the roof deck, that is absolutely going to be a problem. You need to allow an inch and a half of space between the top of your insulation and the bottom of the roof deck. Do not close off ventilation to the unheated spaces. If you have access, then I would drywall the ceiling and then lay the batts on top with the vapor retarder down against the drywall. Use only one vapor retarder. If you are adding more layers on top they should be unfaced.