He shouldn't let you go through all of that alone. I get emotional when I drink too and it can be really stressfull sometimes. As you mentioned, it is really a deeper problem because alcohol can fire up your emotions. If you're putting up a "happy face" but you're sad or going through something, you're most likely going to fall apart when alcohol kicks in. He should be talking to you more about your mental state and figure out why you get emotional when drinking. It's not something you want to happen, you just can't control it, and I totally get it. It's a problem, and if he really loves you, he's going to help you get through it. <3