The best advice I heard and verified in my own life is the following for quitting something.
Keep quitting until you have quit.
Decide that you are going to make a change. You know without a shred of doubt that it is bad for you.
Never doubt the decision.
Step 3: (if needed)
If you fail, repeat steps 1 and 2.
How To Track Your Way to Success!
The only metric I would suggest you track is the amount of time (mins, hours, days, weeks) that passes until your restart.
If you can shorten this time you are on the path to success.
If you ignore the fact you are off course then you are heading in the wrong direction.
The hardest part is to not ignore the truth that you have committed too.
Ignoring a problem can feel good in the moment but it delays the pain. We all know this.
When I wanted to stop drinking alcohol, and I would drink again, I stopped worrying about how many failures happened and I focused on starting again.
I would restart my journey.
It took me about 3 years.
The last time I opened a beer I took one sip and I threw the rest away. That was my last drink.