Help expressing myself? ?

Hi! So, I have quite an issue. I need to find a way to express myself and create something. I was thinking that I would write something... just write and see what happens. I do keep a journal, but I was thinking something along the lines of fiction. I just have trouble writing without being self conscious of what I'm saying and being over critical. So, I'm looking to y'all for advice. On writing without wanting to tear my hair out, about refining my writing style so I won't have a reason to tear my hair out, and any other useful advice you might have. Thanks!