You don't need a niche - write about everything.
Similar to how you like to read a variety of books and enjoy different interests, so does your audience! You also don't know how good you will be at writing on a topic unless you try.
I love the freedom to write about whatever I want, sometimes people will be interested and sometimes they won't. That's a fact of life. But that shouldn't stop you from sharing your stories and experiences - you never know who it might help or what you will end up learning about yourself.
So yes, write about everything you can think of; go where your thoughts take you!
Thank you for reading :)