Conflicting models & time management

Hello all! Yesterday I blocked off a couple hours to respond to emails and send follow ups to prospects. This morning I’m doing my thought download around one particular email and I’m not sure if I’m doing the models right.
Scenario: This person had a free call with me. During the free call I promised I would email 4 different resources. I did not yet have these resources made. I hoped some of them I’d be able to find online and send her. When it came time to batch my emails, I saved hers for last. I had about 20 minutes to get her email out which resulted in two thoughts that conflicted with each other.
Thoughts: I need to write this email in 20 minutes. It’s going to take longer than that to find/make the resources I promised.
Feelings: Conflicted, indecisive, annoyed
Action: Found 1 resource, then tried to think of how I could get around spending time looking for the others, found the other resources, spent time thinking about how to get around making the ones I needed to make for her, made the resource.
Result: Spent 2 hours on this task.

Question 1: How do I use the model for scenarios like this that have two conflicting models at the same time?
Question 2: I realize now I should that as soon as my call with this prospect ended I should have blocked off separate time to find/create her resources. How do I manage my schedule when new things like this come up? The next 3 weeks are completely scheduled up. Is it ok to rearrange your schedule or do you use your free time?