Scheduling

I have to make my own schedule for work (I'm a private practice psychotherapist), and I cannot seem to set up a consistent system to keep me from 10 back-to-back sessions in a day or 3 sessions spread out over an entire day. I will end up with some space but then someone needs to reschedule or has an emergency so they need a session right away. I legit love what I do and I am getting so mentally fatigued I feel like I'm dissociating or in a waking dream at times. How can I take myself from 9+ clients a day to something more like 24 spread out over the week? (Bonus points for answers that also won't entail letting anyone down!)