Hi Jo,
BT is right, cocaine makes you incredibly selfish in all aspects, it also can stir up aggression. He wont be thinking of anybody else in any of this. In fact sorry to say, but the fact your father has passed away to him, will just be an excuse to use and have a reason.
I used to joke that my husband just needed the day to end in a Y to have an excuse, its as simple as that.
Blocking his number will give him a reason to kick off and moan about you doing that to your mum, if I was you, I would just ignore his calls, or get your partner to answer the phone.
You are right to be worried about the funeral, in my experience, he could possibly start an argument, be an idiot, embarrass the family. The best thing you can do is remain calm, try to act totally normal to him, dont give him any looks or say anything, much as you may want to. Dont give him cause. I’m sure he wont kick off in front of your mum anyway, it sounds like he’s playing the victim to her.
Stay strong, take all the hugs you can get, stay level headed and always remember, his actions are NOT your problem or your fault.
x