I can tell you before you even try it, 'cause i used to have that setup, that if you connect it all correctly then it won't happen.
You shouldn't be able to hear your voice in the headphones until you choose to monitor the vocals in your software. Unless the tape to ctrl room button allows the inputs to be routed also. But even if this is so then, unless you have the tape to mix button pressed, then it should only record the vocals.
Do this test for me: Connect your monitors to the main outs of your mixer, and outputs of the soundcard to the tape ins. Have everything else off, set to zero, and disconnected. Play music on the pc, and you shouldn't hear it in the monitors unless you press the tape to mix button. Unpress this button, and press the tape to ctrl room button, and you shouldn't hear the music in the monitors. But put on your headphones, and turn up the ctrl room knob, and you'll hear the music in your headphones.
Now plug in your mic and you should hear this on it's own in the monitors(watch out for feedback, ouch


), and maybe not in the headphones. If you do hear it in the headphones, then great, there's still nothing to worry about. If not, great also. Now connect the tape outs to the soundcard inputs, and choose to monitor the vocals in the software. Now, if you couldn't hear the vocals in the headphones before, you should now.
Everything should be working fine, and you can connect the monitors to back to the ctrl room outs.
Like jjsellers89 said, (s)he managed to record the vocals and hear the recorded track in the headphones(without it being rerecorded), so it is obviously all connected up right. I believe the only thing missing, is that jjsellers89 has not chosen to monitor the input(vocals) in the software.
I have explained how to do this is protools(I button) and audacity(edit, preferences, choose "Play other tracks..." and "Software playthrough"). In Cubase, it is the button beside the record enable which looks like a horn(if you hover over is says monitor). The will be an equivalent in most, if not all, modern recording software.