The BodyFast Coach doesn't seem to have enough information about you and your progress. Please try to stick to the plan and rate the week after finishing it as unappropriate. The Coach will use this information when creating the next plan.
You can also use the plan editor in order to make your plan more suitable. To do so, simply tap on "change times".
If you don't like your current fasting plan at all, you can abort the week in the fasting tab.
To do so, tap on the circle symbol with the three dots (at the top on the right side) and on "abort week". You will then have access to all the plans again and can choose a new one.