Angry, upset and confused

My partner is the most loving person I know, until he has his little strops that is. So today we've had a disagreement over my dog of all things because he was ill whilst we were out, I've had him way before me and my partner met and means the world to me and my children. My partner isn't an animal person and doesn't like the dog so he thinks I should get rid of him because he's a "nightmare," obviously I've said it'll never happen. His respond to this was to storm off upstairs and not talk to me for the last 2 hours. He's now come down and informed me he's going out because I couldn't be bothered to go up and talk to him. The thing is I know he'll now go up to the bookies and lose money we can't afford. 

He can be so childish at times and blames me for not apologising for something I don't feel I'm to blame for, not only that he's going to lose money we need especially as we're due to move soon, I have three children to provide for and I'm pregnant with our first child together. 

I'm so angry/confused/upset I want to cry.