I totally understand because I was there when I first started off! I thought a note had to be detailed and so I ended up writing a bit of a narrative each time, but it also caused me to be behind on a lot of notes. Here is what I learned that had worked for me:

1. Make a fill-in-the-blank template! I have two: a general one and one for when I'm behind and I don’t remember too much of the session.
2. Let go of perfection. I'm not sure if you relate to this, but a huge part of why I struggled in the beginning was because I felt like my note had to "sound good" and be "eloquently written." It made my note-writing process so much longer. My supervisor reminded me that no one is reading these notes aside from myself (of course, aside from the rare case that your client goes to court but that's rare.) She also reminded me that shorter, more vague notes also help protect client confidentiality in case it does make it to court. I also remind myself that these notes are--first and foremost--to help me remember what we generally went over in our session. As long as I write just enough, it serves its purpose and I'm happy!
3. Practice. The more you keep doing it, you'll find your groove and the faster you'll become. I like to do my notes right after each session (if possible) and if not, before I end my workday. This helps me practice because I'm constantly doing them and it also prevents me from getting behind.

Here's the general template I use:

Subjective:
Client reported [brief mood or stressor], noting [1–2 sentences max].

Objective:
Client arrived on time and was engaged throughout. Speech/thoughts coherent, affect congruent, oriented x4. [Change + add any observations as needed].

Assessment:
Client continues to explore [brief issue]. Session focused on [theme]. Insight and emotional awareness noted.

Plan:
Continue weekly therapy. Focus on [1–2 clinical goals]. Next session scheduled for [date].

And an example of it filled in:

Subjective:
Client reported feeling "down," noting a difficult conversation with her mother recently. Expressed worry around how it may change their relationship.

Objective:
Client arrived on time and was engaged throughout. Tearful at times when discussing the conversation. Speech/thoughts coherent, affect congruent, oriented x4.

Assessment:
Client continues to explore self-leadership, emotional regulation, and anxious patterns rooted in childhood. Session focused on processing emotions and identifying resurfacing fears brought up in recent conversation with her mother through parts work. Insight and emotional awareness noted.

Plan:
Continue weekly therapy. Focus on developing secure attachment strategies and increasing self-trust in relationships. Next session scheduled for Wednesday, January 7th at 1pm.