Removing Feedback on Vocal Track

Hey everyone.
I recently recorded a vocal track in GarageBand - however, there is a noticeable amount of feedback noise (hissing, primarily) in the background of the track due to the poor recording set up and lesser quality mic.

I tried dipping the volume during silent parts to minimize how noticeable it is, but this only made it more obvious.

I was wondering if anyone knew any tips for settings to remove the feedback without degrading the quality of the vocal track. I'm assuming some quality will be degraded, but I would like to minimize it as much as possible.

The vocal (singing) track is accompanied by piano, so there is not too much to drown out the feedback beside tinkering with the actual vocal track.

Any advice or tips are greatly appreciated.
I also have Logic Express and Ableton Live if those programs are better for this task.

Thanks!

Thanks for the EQ advice. I hadn't even thought of that, which makes me feel a little silly.

I will definitely re-record with better precautions for quality for future projects, I just don't have the opportunity for this particular track. I never record with a mic, always digitally directly to the program, so this is a new experience of trial and error.