Psychotherapy (not progress) notes how-to

Hi all! I'm wanting to try my hand at keeping psychotherapy notes (in addition to the progress notes in my EHR required by insurance), but I need some advice as to how to store and organize them. I have been writing progress notes for years; over time, they have become more and more vague in order to increase client confidentiality. However, this has meant that I have not been writing down details of client's stories (other than the occasional genogram). I'd like to see how keeping psychotherapy notes feels to me, but it seems overwhelming to have two sets of notes and to store them in a secure way (my EHR does not have a separate section for psychotherapy notes). For those of you who keep two sets, how do you manage this? Thanks!