Cryptpad, essentially google docs/sheets/forms e2e encrypted. It does include collaboration. https://github.com/cryptpad/cryptpad
Immich, google photos self hostable, with share options https://github.com/immich-app/immich
Nginxproxymanager manages certificates and proxies to self hosted stuff through nginx https://github.com/NginxProxyManager/nginx-proxy-manager
Great self hosting stuff!
I can recommend traefik as proxy too
I recently tried the Collabora Online integration in Nextcloud, but was quite disappointed with it, the right-to-left button was greyed out for no apparent reason, and creating shapes and moving then around felt sluggish (clicking the rectangle tool directly added a rectangle in the middle of the slide, which I could then drag around and resize, but the transformation tools seemed buggy and didn't really work well).
I'll certainly try out Cryptpad