Garageband Playback Monitoring Glitches

Hi! I'm currently using Garageband with a JEEMAK USB Microphone and over ear headphones. The process of recording singing is currently driving me insane because at random intervals the playback monitoring will start to have a big delay so that instead of hearing my own voice into the microphone through the headphones, I hear my voice from about a second beforehand, making it impossible to keep singing. This happens all the time, sometimes every 10-20 seconds and sometimes every minute or so. Nothing changes when I unplug the mic, quit Garageband, or even restart my computer. Does anyone have any insight into why this is happening or how to fix it? Any advice at all would be massively appreciated because the situation as it stands is making me want to throw the computer, the microphone, and then myself, into a large river.

Thanks,

T