I keep starting healthy routines and then dropping them when my energy dips. How do you make them stick?

I am trying to build a simple self improvement routine: move most days, cook more at home, keep my place reasonably tidy, and do a little planning so I am not always in crisis mode.

I can keep it up for a week or two and feel great, then my energy tanks and I slide back into old habits. I am in perimenopause and have PCOS, so energy and motivation can be unpredictable. When I hit a low patch I skip workouts, meals become random snacks, I stay up too late because I feel behind, and the next week is basically me playing catch up.

I do not want a perfect routine. I want something that survives the bad weeks.

For people who have made routines stick long term, what does your "minimum viable" plan look like when you are tired or stressed? How do you decide what to keep and what to drop without quitting entirely?

Some specific things I am stuck on:

1. Do you keep the same schedule every day, or do you build in planned low energy days?

2. How do you reset after a rough week without turning it into a spiral of self criticism?

3. Any practical tips for keeping food and movement simple without feeling like you are failing?

I would really appreciate ideas that are sustainable and do not depend on high motivation.