Sikhis is a journey.
It is a long path, it is not the easiest path one can walk.
Sometimes, somewhere down the path, you get tired and give in to sin, that happens to everyone, whichever path they walk(be it Sikhi, Chritianity, Islam, etc.).
There is only one thing you can do, and that is ask Waheguru for forgiveness en pray that He may give you the strengt to refrain from sin the next time.
You can't expect from yourself to win every battle from kaam at this stage in your journey.
At the beginning of the journey kaam will win every battle, but the further you get down the path, the more battles you will win from kaam, but only at the end of the path will you be able to win every battle.
So when kaam knocks you down, you just need to get back up on your feet, pray for forgiveness and carry on down the path.
You managed to stay clear from kaam for 1 month, next time you try that might be 2 months, then 3 months, and one day you will be able to keep it up for the rest of your life. Believe in yourself, and believe that Waheguru will forgive your demerits if you do good deeds.
Other than the Gurus, have there ever been people completely free from sin?
Have a little faith in yourself, you will get there one day.