I'm so sorry about your brother...I hope he finds recovery.
Also it took a lot of guts for you to reach out for help here, so welcome. :ghug3
Most people can't quit drinking (or more accurately, STAY quit) without some sort of help. For some, writing out a plan, spending lots of time on this forum and finding alternate activities to drinking - you gotta find something to replace your drinking with - is enough.
For others, groups like AA, SMART Recovery or some sort of hospital-based program works. I've tried a lot of ways to stay sober and am committed to AA now...it's not for everyone but meetings are free and new people are always VERY welcome.
Do you have a doctor you've confided in? I don't know how much you've been drinking but quitting cold-turkey can be very dangerous; detox can kill.