Learning the Skill of Honoring Decisions Ahead of Time

I am trying to change a habit of not exercising into a new habit of exercising four times a week in the morning, first thing.

I simplified it for myself, constrained it to the exact activity I will do, days and times, and calendared them.
Alas… morning comes and I hear the negative chatter and it’s always much faster and more reasonable to me at the moment than to honor my commitment.

Now, as far as a compelling reason – it’s pretty straightforward – I want to be fit, strong, look and feel great. I also want to feel comfortable taking off my clothes in intimate situations.

I read about neuroplasticity and how the more we repeat new behaviors, the stronger the new pathways get and the weaker the old and unwanted pathways become, so I get how the new habit will be formed, I just don’t have a hold yet on the skill of letting the higher brain take command in the morning over the lower brain.

I’m not beating myself up but I don’t want to worry about this problem a year from now. I want to figure out the skill and let it run.
What am I doing wrong?