OP, lots of "why the hell did you do that?" here and justifiably so but don't get too down about it. If you're inexperienced or you just don't know....well then that's the way it is. Just chalk it up to experience and don't do it again.
I'd suggest some searching and reading up on the barebones basics of how this stuff works to educate yourself. An amp tech will charge a "bench fee", probably 60-80 bucks to sort of diagnose your amp and see what it might take to fix it. They should be able to at least give you a loose estimate of what it might cost. It's then up to you to decide if it's worth it or just to hell with it and get another amp.
I find that the more expensive the mistake....the less often it's repeated. This is coming from a guy who thinks if you can't drive a stickshift, know how to check your oil and be able to put the spare tire on, you have no business owning a vehicle. Walk or ride a bike if you can keep the bike working.
Same applies here....learn the basics or just play an acoustic bass or sing the bass part.
