Hey.
I hate yelling because there was a lot of it when I was a kid :-(
It can be something of a reflex to yell, I understand that, but I also understand (in my better moments) that yelling doesn't help the situation it only harms it. Unfortunately one doesn't see that when one is reacting...

Part of it sounds like anger management.

What do you do when he yells? Do you yell back, or raise your voice to try and be heard? Do you withdraw?

Maybe you could have a chat to him about it when he is in a calm frame... Sounds like both of you want the yelling to stop and maybe you guys can figure out a strategy together and you can help him implement it.

One thing that could be helpful is to chat to him when he is calm and figure out something that you can say to him at the time when he is yelling at you. Something to be said in a firm voice (or the firmest voice you can manage). Something that he agrees on when he is calm. As an example... You could say something like 'You seem really upset about this right now so I'm going to walk away now and we can discuss this in a few minutes when you are feeling calmer'. And then... Walk away.

Then he needs some strategies of things he can do to help calm himself down. Things like taking a few deep breaths. Having a glass of water. Maybe doing some physical exercise like going for a run or having a punching bag or something like that.

It would be important to talk to him about how it is going to go when he is in a calm frame of mind so that you can both figure out the phrase that you are going to say (so he agrees to it when he is calm so he is less likely to feel angrier when you say it when he is upset). It is also important that he understands the rationalle for you walking away.

Dealing with stuff like this can be hard...

It is important (I should say this) to only use this strategy when he is yelling... If you are worried that he is about to start maybe there could be another phrase like 'Do you need a minute before we talk about this?'

It is important to talk about the issues... But usually progress won't be made on the issues when one person is upset and yelling also tends to upset others.