First, I hope you're not 2nd guessing your decision to have this idiot deported. This situation had a high potential to totally mess up your life and of course you did what you had to.
Your mom and grandma clearly have some issues and have made some big mistakes. I wish you had given your age, but when a situation is this dysfunctional, it's always true that the older generations have messed up. Let's just say it doesn't sound like you grew up in a happy healthy home with mom and dad happily married and a couple siblings.
When you ask how to handle this, the most obvious thing of all is you need to break free from it. If this erupts again, you may not escape from it unscathed, and like I said, this could mess with your future. Find another job (or 2) and figure out how to get out of that home. It's toxic and you probably don't even see how bad it is.