Try removing the "date battery" for your camera--it's a small watch battery, about the size of a nickel. Check to see where it is for your camera.
This will clear its internal memory (it will forget that it had any problems at all!) and all the settings will be reset to factory defaults. The error should be cleared and it should let you load the tape.
On the other hand, if something is MECHANICALLY wrong and you PHYSICALLY cannot load the tape, it sounds like you could have forced the tape and bent some piece of metal inside the deck--that might be what's preventing it from closing. But the error and DC adapter
Worst comes to worst, it probably is still under warranty. The annoying thing is now you have to go through the warranty process with Sony if Best Buy doesn't offer a warranty, and this involves shipping your camera to their repair center, waiting a few weeks, having it come back, and potentially losing it or damaging it in the mail--not good.
So first go to Best Buy and check if they offered a warranty or they sold you an extended service plan on it. If they don't, it might be time to call Sony with the problems and let their