Me and my girlfriend met 2 years ago and things have went great and we always agreed upon not drinking and not using other substances which showed me our morals aligned. At the very start of the relationship I established that I will never agree with drinking and neither will I marry someone who drinks. She was totally cool with this which is why I thought nothing of it at the time. I myself have grown up seeing alcohol destroying families and even my own which is why I don't see the appeal of drinking. She also has had alcohol family issues growing up but does not have trauma from it I guess. Trauma aside I do not want to spend the rest of my life with someone who drinks. My girlfriend is willing to set boundaries such as no more than 2 drinks and having drinks with lower alcohol content. I 100% trust her to not come home drunk or exceed her limit. But then again I have never been with her when she has drank but I know the most she has had was a buzz. Even with just a buzz when she sent me videos and I could see slight alterations in her behavior and that really hurt cause it felt like I was losing who I fell in love with. I totally appreciate the effort on her end to compromise but I truly don't think I can remain happy for a lifetime with her if she continues to drink. She is the perfect girl in my eyes besides the drinking which is why I am so perplexed on what to do. Am I controlling for asking her to keep her promise about not drinking? This has also really become an issue when she turned 19 which is the legal age where we live and a part of me is telling me that this is just a phase she is going through (having the freedom to go to bars, clubs, etc) but I also don't want to stick around and get hurt in the end. She has also said she doesn't want to drink after the age of 21 but I'm not sure how that can be guaranteed and also if I am able to deal with drinking until then. She has drank 3 times in this relationship (once before turning 19 and twice after) and every single time she has drank I feel absolutely sick knowing that she broke a promise and is becoming who I thought she never would. I become full of emotions such as anger and sadness whenever she does drink and I do not know how to put that all aside and just be okay with her drinking.
TL;DR
What I am asking from all of you is to let me know if I am being controlling for not wanting my gf to drink and what I should do moving forward. Is it on either of us to change our morals or is it time to go separate ways?