Even I enjoy using rwtxt for capturing my thoughts. I too have hosted it on my own server. However, as much as I enjoy using it and would like to use it for journaling, am not sure about controlling the access.
I installed it on my own server (there’s a free hosted version too) and created a private domain for my diary, another one for notes and also one, which I can use to share notes with others.
Your setup really sounds interesting to me and I would love to have something similar setup. Can you please elaborate on this a bit?