There are very few hard and fast rules concerning how one should use Steemit. :c)

Some post multiple times daily.

Some post once every several days.

Others post daily.

Others don't post but comment a lot.

Others don't even comment and just "curate".

One thing that is recommended is that every post include a picture (because the picture will show in the list and will draw more attention.

That being said there is no hard rule about it needing to be a different one every time. Maybe you could create a really compelling composite image that kinda 'represents' you - and use it every single time you post something that you lack a unique image for. :cP

Incidentally it sounds to me like you lead a very very interesting life. And another thing about Steemit is that you don't have to have a single topic.

Of course, over time you will develop your personal brand and you will attract fillowers who want their dose of @ketflan whenever she can. :c)

Steemit is a garden. You recently planted a couple of seeds - and as you water them you'll find more seeds to become available. This is how Steemit works. ^_^