Same for me, just in the process of updating my mail adress everywhere again right now.
My renewal was just coming up and I also couldn't justify it. I've switched to a personal domain with my E-Mail and use Infomaniak for mail, calendar and cloud storage an Keepass as my password manager. Positive side effect, I only pay half of what I've paid for Proton.
Saber should be exactly what you need:
https://github.com/saber-notes/saber?tab=readme-ov-file
You can take handwritten notes and supplement them with text and images. It can also sync directly to your Nextcloud Account or sync via a Saber Server from the developer.
I used it for a while on my Boox tablet and it worked really well without many bugs or hiccups. I only switched to Notesnook because I stopped taking that many handwritten notes that had to be synced as well.