I wouldn't call that lying... because if you had been able to tell her, you would have... so yes, there was more you need to share, but no you can't do it all in one session and surely not at the end of session. Patients are usually already upset that there isn't enough time to cover---or they are afraid to get into a topic and not be able to close it up well enough to not feel alone with it again...
This is very normal...so many things to share with the T!!! I'm glad she asks you...just in case...and it's fine to make a list of things so that you can cover what's most important that week. If you can share some of those topics then that will help your T make a good treatment plan for you...because it is all about you.