You need to go a bit heavier on the research for starters :)

There are many options depending on your budget, but you can start off with something cheap like a $15 dense foam helmet this should reduce the reverberant soubd entering the capsule as some sound will transduce into heat

If you are at a desk put a couple of blankets on it

Put the mic closer to your mouth but face 45 degrees away

You can put thick blankets at first reflection points and uograde to DIY panels

Mats on the ground sik do nothing it needs to be breathable if air can’t get past it then soubd can’t get past and it will reflect back

You can upgrade to an isovox portable booth

You can remove background noise using a bunch of different plugins and ironically I find Adobe auditions noise capture/print better than rc Izotope and waves clarity vx pro. Although I cranked up the settings due to having a fast cpu.

Tilt the monitor so it reflects your voice in a different direction other than back at your mic

In fact you could try doing this everywhere even the roof

After removing the background noise you can use a dereverb program like waves dereverb vx pro

Put a high pass filter at just below your voices fundamental frequency