I think only you know the answer to that question as to whether you can be a sometime drinker. I have been tracking my alcohol intake for a little over a year, and I was not happy with what I saw. My longest stretch was 27 days, and now I am on Day 1 again. My friends do not think I have an issue with alcohol, but I know that I have been abusing it and using it as a crutch. While I may not be an alcoholic yet, I never know when I might cross that line. I think you are wise in seeking out advice here, and I think you will get a lot of support regardless of what decisions you make.
And if you friends will only be friends with you because you drink or if you only have to do "drinking" activities, maybe it's time to find some new friends or find some new activities you can do together that don't involve alcohol.
I do think that being self-aware is the first step, so maybe quitting today isn't the answer, but start tracking and start journaling about when/why/how much you were drinking and see what it sparks in you.