Millions are declaring August to December their lock-in season. The energy is real. The math is brutal: seasonal discipline has an expiration date built into its name.
Two people with the same goal will produce radically different consistency. The variable is not discipline. It is whether the goal is connected to something worth being uncomfortable for.
You have restarted your goals so many times that restarting has become the goal. The problem is not your discipline. The problem is what your brain does with a clean slate.