dead car

Ok I posted twice now and I got no replies, I have the chiltons book on the fieros, but the trouble shooting guide is lacking sincerely....my 85 fiero se 2m4 4 banger first had problems with acceleration, and then starting.......now it wont even start period......and when I jumped it which the battery is only like 2 months old....when I jumped the car the rpm shot up to 3k and didnt go down at all. Tomorrow I'm replacing the throttle body system, but that doesnt exsplain to me why the battery is practicaly not working when just a day before it was starting and the battery was fine... but suddenly overnight the battery gets drained?? doesnt make sense and no I didnt leave any lights on or anything such as that.. so if anyone has any ideas or past exsperiance that would be great cuase I would like to try and fix it myself before taking it to a shop and paying out 500 dollars for them to check my tire pressure thanks.

charge the battery disconect it overnight next day connect it and see if it starts, if its battery then it wont start
if it does start then you have something shorted out draining or something not shutting off like fan etc

take your negative battery cable off and place your test light (or 12v lamp with leads soldered on) between it and the terminal. with your key off, all your lights off and the fuse for your radio fuse pulled, the light should be off. If the test light glows, you have a power draw, pull other fuses until the light goes out. The fuse that turns the light off protects the malfunctioning system and you can diagnose from there.