Coping with overwhelm/3am thoughts

I’d love your advice on the best approach when I’m feeling overwhelmed. I have several major things going on in my life and am feeling pulled in multiple directions. My workplace is being relocated and my role restructured, which means a lot of extra work, plus I have three family members with significant health issues that are worrying and require appointments, treatment etc, and of course I’m also doing SCS (yay!). I’m totally happy doing all of it, but sometimes I feel like I can’t think straight because of how much is going on and how many micro tasks I have to manage, I’m worried that I’ll forget something important. I calendar as much as possible, which really helps, but so much comes up during each day that I’m finding myself awake at 3am and just worrying over all the little details of what I need to do tomorrow. How do I turn off the constant chatter in my head about ‘everything I need to do’. Thanks!