Help! I have no self control!

Have someone else hold your key.
Use a safe with a timer lock.

 

you can use emlalock or chaster.app for example

 

You could post your keys to your self, recorded mail of corse!

 

For a timer, get a k-safe because although the maximum time is ten days, with the revised model you can increase the time while it's counting down, so get in the habit of dialling it back up to maximum every day until you crack, and then it'll be nine days until you can get release. Another thing you can do is remove the batteries once it's locked and maybe keep them somewhere inconvenient, then when you need release badly enough to overcome the inconvenience you still have ten days to wait. I did the latter for a while and found that not being able to get immediate gratification was a good incentive to carry on waiting.

 

This kitchen timed lock box goes to 41 days and is under $40:
https://www.amazon.com/Multi-Purpose-Kitchen-Containers-Addiction-Excessive/dp/B07XP2ZP6P/

 

The trouble with that type is that there's an emergency release, same as the timer padlocks.