<human>: Hello reddit, 20/f here.

My love-of-my-life type boyfriend is leaving in a month to go to boot camp. I've been very supportive of him and never once told him I didn't want him to go...

...until I drank around him.

The first time we were alone in his apartment. He had Guinness in his fridge and offered me some. I don't remember exactly what happened, but apparently I cried and begged him not to go.

The second time was visiting some of his family. They offered me some wine. He begged me not to drink, that I act "really immature and out of line" when I drink. I laughed him off and had a glass and a half of wine (I'm an extreme lightweight). Apparently I, again, begged him to stay with me and to not leave.

I know this hurt my boyfriend a lot, and I really don't want to act this way. It's not how I feel about him leaving, and I don't know why I apparently turn into this mopey version of myself. 

Reddit, is there any way I can still enjoy a glass of wine like a normal human being without bursting into tears? Or should I just abstain all together when we're at social functions. I am turning 21 when he's gone, and I don't want whoever hangs out with me to deal with this dr. jekyll/Mr. hyde version of myself.

Can you succinctly summarize the text in 1-3 sentences?
<bot>: I turn into a depressive loser after just one glass of wine or beer, and would like to find a way to change that.