OK
What type of stuff is it he's buying.
Or is he salvaging?

So making sure the halls are clear.

Tillie has some great advice and experience.
I had to put my clutter in a storage unit. Or I couldn't keep up with what others were adding to our hoard.

So limiting clutter to designated areas
And a regular purge routine. Helps .

What's your trash pick up look like. Is there a heavy trash pick up day?

Yes it is taking over living spaces. Also our garage, rear yard and driveway. No loses. No mental health issues. I am a bit ocd and I clean constantly on weekend bc nothing is ever in its place or finished because there is so much stuff. Our girls are in a small room together bc one of our rooms upstairs is so packed you can barely get in. I have pictures

Hi Trish

I know what I would do. But sticking things there only leads to anger. Lol.
But seriously though. I'm glad to help if I can.
But I'm a hoarder. Others here give great advice.

Start with boundaries.
And it would be helpful for some us to know to what degree of anxiety you experiencing. If you see a counselor or therapist, or on medication.

What types of hoarding does he have?
Is it taking over living space?
Is it hazardous? Or expensive.

Is he OCD, ADHD,BIPOLAR?
experienced any major losses lately?

I don't know that I can give you a good solution or not. But I will listen if you wish to share.