I can't get my ollie technique right...?

It sounds like your trying to hard to do the trick.Just relax put your front foot about an inch behind the bolts and your back foot directly on the tail.Come down with your back foot and when the tail hits the ground slide your foot up and take your backfoot off the board a little and it will pop evenly and then land.Also if your having problems with stability mayb you should just skate around for awhile and not worry about tricks until your very stable on your board.Tip try to land with your front foot on the bolts.