Remote work with 4yo is destroying my sanity

Anyone else WFH with a young kid in the house? My son just turned 4 and daycare is $2,100/month so we pulled him out for summer. I thought I'd "just manage" but I'm losing it. Had a call with my director yesterday and my kid knocked on the door THREE times in 20 minutes asking for apple juice. I pretended I was on mute but I'm pretty sure everyone heard "DAAAAD WHY?" in the background.

Wife's at her office 3 days/week so I'm solo most days. The guilt is real - I feel like I'm letting both my job and my kid down. How are people actually pulling this off?