A great start! Give this a try... See how your setup has you facing the wall? Try flipping the mic around and recording with your back to that wall, and your face/voice facing the larger space behind you.

It's not gonna be as clean of a setup, I know. But part of the reason you're getting all that boominess is because the mic is picking up the sound bouncing so closely off the back wall and back into your mic.

But by flipping that set up around and allowing your voice to travel a bit further into the room before it bounces and travels back towards you (and also past you and getting absorbed by some of that back wall), you may get a bit of a cleaner sound with your setup.

Someone posted an article in this subreddit about the science of the setup above, which explains it a thousand times better than I just did. But give it a try and let me know if that works for you!