Sounds like you got some really strong stuff. All I can say is to keep in your mind that what's happening isn't real, and it's just that you're intoxicated, and that after a while it'll pass of and you'll enjoy it more.

I've felt the couch lock you described, where leaning my chair back a bit would make me freak out cause I'd think it'd fall over, even though there was a wall right behind me that wouldn't let me fall, which made it funny after I realized that.