Is my tarantula gonna die?!?!?

Recently i purchased a rose haired tarantula! At first it was fine, keeping to itself mostly. Yesterday i dropped some crickets in there and it ate a few of them happily. I woke up this morning and it was laying on its back , looked like it was dead, kinda freaked out i blew on it softly and it rolled over and stumbled away. Now it is just sitting in a corner reared up randomly flashing its fangs. She tries to back up the side of the tank backwards but almost gets vertical and falls off... Any ideas on whats wrong with my eight legged lilttle friend????