I had the same thing with quitting cigarettes.
I must have quit 100 times or more. Sometimes it lasted for part of a day, someties a few days, sometimes a few weeks or a few months. Once for almost 2 years and then I thought I'd have 'just one'. A the time, I felt like I was going around in circles. Eventually, I got sick of that and I thought, if I'd just strung all of my time quit together rather than interrupting it with time smoking, I'd have a long time quit.
I got tired of the feeling after a relapse. I got tired of having to quit again. I learned a lot from each quit attempt and that helped me.
I put those lessons to use and remembered how crappy I felt after relapsing. I learned that 'just one' was an illusion that would get me EVERY SINGLE TIME.
I haven't relapsed at all on the alcohol, but I think it's because I relapsed so many times with cigarettes that I learned from that.
One thing that helped me actually was to commit to 1 year no cigarettes. I KNEW I could handle 3 months becuase I'd quit for that long before, so there was no reason I couldn't handle a year. Once I did that, it took out the option of relapsing and I knew that after a year, the cravings would get way better. That was how I quit for almost 2 years the first time. This time, I set my goal at 2 years because I almost made it that long before, I can make it longer this time. Truth be told though, I would like to avoid ever having to quit again, so I kind of plan to stay quit for good.
It sounds like you're getting tired of this "in and out" pattern, so why not commit to a longer period of sobriety??