kyndyl
I wouldn't discount your ears (unless you're tone deaf

) Do you have a commercial CD that you really like/admire the way it was mixed and sounds? (I have a small collection I use as 'reference" depending on the style of music: Steely Dan's Aja, the recent Robert Plant & Allison Krauss, Sgt. Peppers, Stevie Nick's Belladonna, Doobie Brothers Liv'in on the Fault Line, Synchronicity, Layla...) How does youtr 'reference CD sound with absolutely no EQ or other enhancements? It's important to really study your reference on different systems so you can determine what's different in your room: boomy, thin base, excessive highs, or a bit muddy? These are the areas that you need to learn to not overcompensate for in your own mix, otherwise the cuts and boosts may stand out in other listening environments.
things to consider:
Monitors- are they sitting 'solid' on your desk/console- if so you may have some 'coupling' whereas the surface of the desk/console becomes an additional source of resonance- place them on some mouse pads, acoustic foam, monitor wedges.
Are you mixing from a corner or in the middle of a wall? corners are problematic, especially for low freq's... which is why they are typically 'trapped'
Are you sitting (your ears) at the rooms mid point(either front-to-back, or side-to-side? standing waves are a real problem at the mid point...
heavy blankets will help to an extent, as will heavy drapes. Generally you don't treat opposite parallel walls. in the exact same location, as you want some reflectivity, otherwise ther's a tendency to add too much verb. The goal is not to 'kill' the rooms acoustics, just tame those frequencies because of the shape/configuration are creating problems.
carpeted floor? if so I wouldn't do much of anything with the ceiling, though a "cloud" type diffuser above the mixer/keyboard is helpful.
If you don't have to close the door(s) into the room, try leaving them slightly open
Pictures on walls - put felt "bumpers" on the back of the frames so they can't vibrate
try changes one-at-a time so you can see which ones are making a difference and which ones don't seem to change much of anything
Because most of us are in rooms that were not originally designed or built to yield pristine acoustics there is no absolute correct approach, but IMHO, I don't believe that the next plug-in will solve everything. Even the room correction software requires the engineer to be aware of where the corrections are/were made. I have the JBL's with RC and with all my acoustic treatment there's still a cut at 92 Hz, so I'm always mindful not to make much in the way of boosts at that freq plus or minus 10 Hz-
good luck
and you can always post a mix and see how others would approach it, albeit a bit humbling at times