I’m ruining my relationship

I’m ruining my relationship. My ex and I have been on and off but seem to always try continue mostly Because I convince him I will change . Which I do for the most part except a few things that I keep doing that are destroying us and making him end it. I lose control of my emotions when he’s about to end it ( sometimes in front of son) or I feel he’s instigating problems at me and I also kept trying to get him to apologize to my family. When we got back I agreed and promised to not do any of those things. This past weekend we went to universal together for our sons birthday. It went amazing!! But the last night I messed up and need advice on how to change how I get. We both were having a couple of drinks, he didn’t drink too much but I had 2 glasses of wine and a double . Which normally wouldn’t do much to me but I had t eaten or drank in a while so it made me “ black out” when we got to the car. My son fell Asleep and last I remembered I was slurring so bad. After that I apparently brought up my family, and everything I promised I wouldn’t bring up and it made him dump Me. I woke up more sober in the back seat while we were driving home from Orlando. I asked him what happened and he said it’s over. So I asked him for the card that had extra tickets on it ( a picture of it) so I can call the next day and separate mine since I paid for it. His words were “ nope! You don’t deserve these tickets you’re not getting shit.” And refused to Give it. I kept ( calmly ) but asking for it for about 20 minutes we went back and fourth talking about it. My son was in the back moving because our convo was making it hard to sleep . Anyways he told me I messed up there too. I lost control in front of my son instead of staying quiet like an adult. I mean I know I shouldn’t ever argue even calmly in front of kid ( sleeping or not) but I seem to not be able to control it when I feel I’m being bullied or dumped again. How can I control this? For my son?