Listening Room or Components or my ears?

Agree with the advice on treating your room including adjusting the speakers toe-in and your listening position.  Focals can sound a bit harsh or sibilant especially if you’re sensitive to sibilance.  You may want to demo speakers with a different sound profile if the room treatments don’t work.  You may prefer speakers with a rolled off top end instead of an elevated in room response. 

Six feet is very close together.  Can you move them apart and toe them out more - get out of the tweeter's death ray?

See an audiologist first, if you want to avoid or postpone a wild goose chase.

My suspicion is that the Focal speakers are the biggest culprits for your treble character. 

There are so many ways to remedy this but I will attempt to give you the easiest vs the most comprehensive solution.

As others have recommended, getting panels on your first reflection points may help with this issue.  I would recommend gik acoustics or doing a DIY panel build.  Not hard.  Just need some stiff insulation and fabric and frame.

Another thing you can do is get a Umik-1 and use room eq wizard and see what your frequency response looks like both on var smoothing and at 1/6 smoothing.  You may be able to determine where that resonant frequency is and use a notch EQ filter to reduce that band.

And if you really want to go spend some money, yes maybe it's the focals.  I recommend tektons for detail without glare or harshness.  Double impacts are my go to recommendation under 5k