I don’t think I’m being childish. I just want to be able to make simple requests and not have him explode onto me and with our son in the next room.
You're not being childish. What you're asking for is completely reasonable and the absolute baseline. More than just respected, you and your son deserve to be cherished and protected.
It's been a few days since you posted this, so things may have changed. It sounds like you're at a crossroads and have some decisions to make. Are you open to heeding the therapist's advice not to return until he truly commits to no verbal abuse? I know he's threatening to hurt your reputation but please believe me, as someone who endured verbal abuse from a spouse, then public maligning when I stood up to him, the truth comes out in the wash.
How old is your son?