Advice!

So my boyfriend and I have been together for almost a year now. I love him with all I have. And he is leaving for basic training to be in the army in 3 months. Here lately, however, he has been drinking more than normal. And when he drinks he gets kinda rude. I have to watch what I say around him now because I don't want to trigger anything and cause us to fight, which has been happening a lot lately. I just don't know how to talk to him about it without him getting angry with me and cussing me out like he does when we fight or when I bring up his drinking problem. Idk how to get him to realize that he hurts my feelings when he yells at me. Any advice on what I should do?