It’s fine. The body doesn’t stop looking for the resources to repair itself just because someone didn’t drink a protein shake within 30 minutes. Most of that is pushed by the fitness industry and/or matters for folks training at the highest level.
Adding a consistent work out to your routine and hitting daily protein goals is most of what matters.
I personally sleep better after i eat but that simply is a life of always eating before bed. Bodies can really like. Bad habits and it can take a long time to get used to change.
I think your fasting change should just work fine. Just make sure you still have the wnergy to push hard in the gym :) Good luck!