There's a dial on the "back" of your blue yeti that has different types of audio pickups, go read the manual, it explaisn what they are and what they do, and experiment.
You shouldn't need a new mic, it's most likely you don't have your audio setup right. A boom arm will move the mic closer to your face, you'll the need to play with the audio settings somewhat because the pickup will be different.
You may just need software to cleanup/enhance your audio: https://obsproject.com/forum/resources/microphone-cleanup-with-adobe-audition-and-vac.7/
Maybe set you headphones to listen to your mic, so you can hear a live feed of what it picks up and troubleshoot it from there.
Audio is a complicated business.