Arrange to see your grandson at your DIL's home.
A nine month old cannot be brought round to visit someone who gets pished and starts cursing up a storm at the baby and his father.
You make arrangements to see the baby, without your husband tagging along, at your DIL's house. I think this will solve the problem re the baby.
The problem re your husband is that he clearly finds this behaviour completely acceptable to inflict on his family. I echo those posters above who are suggesting culturally sensitive helplines.
Good luck.
Lasr two letters continued Jan 24
Bought the wrong Hot Cross Buns 😩
In light of our current weather.......