I know what you are going through. I started having short blackouts in my twenties. I am now 31 and whenever I drank (before getting sober 2 weeks ago) I would blackout, and they would get increasingly longer, sometimes hours. It only gets worse.
I decided I could no longer live with the anxiety and shame, and the fear that one day - any day - I would do something that could never be forgiven and forgotten (I am still amazed at the things I did manage to forget/suppress and that others managed to forgive).
SR has been incredibly helpful for me, I could not have come this far without the incredibly kind, supportive and insightful people on here.
Blackouts are to be taken seriously, and are a sign that you have a problem with alcohol, and - from my experience - that things are getting worse. I hope you will stay on here. I so wish I would have stopped drinking after my first blackout, it would have saved me, and the people I love, a lot of pain.