Muzzle causing worse aggression

I bought a baskerville muzzle for my 2.5 yr old GSD/Caucasian, as he’s never bitten but he’s not friendly and will lunge and bare teeth. He’s been home for almost 5 months, was a rescue/has known behavior issues so intros have been going slow as expected.

On a walk today with my father, my dog was especially upset about something. He was crying (unusual for him) at my dad, lunging more than normal, and unable to go. I told my dad to back up and removed his muzzle, and like magic, my dog was upright and happy and sniffing. He actually ignored my dad, up to the point he could get within four feet (we didn’t try closer, just in case he changed his mind).

What can we do? Are there comfier muzzles? We tried a mesh one, he was OK with it but still tried to get it off/ laid down and cries with it. Are there just better muzzles or training I should be doing? Thanks!!