I'm on my 4th major attempt to lose weight myself. I had given up but became diabetic and am now forced to lose weight or die. At least I know this will be my last time. I will either succeed or die. It's a bit of a relief actually.
Statistically you have a 95% of failing to keep weight off permanently, so... I guess that means you just have to try 20 times, if you can get that many tries.
I look at it this way... I can either whine about the million times I've failed and focus on how hard it is for me to be successful, even slightly... Or I can suck it up and throw my all into trying again.
I just feel better when I force myself to do the latter... But I completely feel you.