This is just my opinion. If he reacted so violently to you texting your ex about your mom needing a lung transplant, then you need to end it. What you experience with him is not love. There can be no love where there is no trust. He does not trust you. He physically assaulted you (tried to choke you). I'm sorry this has happened to you, but this man is not healthy, he sounds very controlling, and he is violent. He has been physically and verbally abusive towards you. There is no question that this is a boundary that a man should never breach with a woman and still have a relationship with her.

I'm confused about why you're confused. He physically assaulted you, he's verbally assaulted you, he's abusing drugs and alcohol and driving. You almost called the cops to protect yourself from him. Considering those facts. What would you tell someone you care about who experienced that?

It does not matter if you were wrong for not mentioning texting your ex (you weren't btw). What matters is he has shown you how he behaves and what he's willing to do to you. I'm not trying to force an opinion on you. But if you were my daughter or my sister, I'd tell you to block this guy's number and never talk to him again.