Do you think it's odd that I save every post on my Instagram feed?
I don't think so, why do you save every post?
I like to look back at what I wrote, it makes me feel good.
If that is what brings you satisfaction, then so be it. It seems like you are pretty organized, which is good!
I'm afraid to delete anything so I like to save all of the posts.
It's fine to save all the posts, you never know when you want to look back at the past. Make sure you continue to look towards the future and not think too much about the past.