All you have to do is unfollow everyone! Literally everyone. Your feed will be blank and peaceful, but you will still be able to maintain a presence on messenger and maintain your profile for people to reach you. You can also still interact with private Facebook groups and things, if you want.
This is what I did, and it curbed my addiction to checking facebook.
After a while, I slowly started following specific people again (mainly just the people I interact with on a daily basis, and the few family members that I can actually stand).
The moment someone starts stressing me out by posting nonsense or clutter, they get unfollowed.
It's very zen, and my mental health has drastically improved from it.
P.S. If you Google "Facebook Unfollow All", there are multiple tools and things like browser extensions which make this as simple as one button press to accomplish. It can be pretty tedious to do manually by hand if you have a lot of friends.