[Stylist] Overthinking when writing

[Vejas Vasiliauskas]

Hi, 
I hope you have all had a great weekend.
I feel that I often engage in two types of creative writing: prompts and assignments that need to be done for class, and also writing for fun. I want to write for fun to keep it up and not just limit myself to assignments. 
I actually have found the school assignments to be easier to do, because they must be done, have a deadline and have some kind of structural requirement. 
But when I write for myself, I find that I often overthink things. I've heard it's good to just write and see what comes out, but it doesn't always seem to be working because I tend to overthink while doing even that. For example, I might have a general plot idea, and start the first few sentences, then tell myself it's realistically not going to go anywhere, even though in some cases that probably isn't true. At other times, I might start a story with a name of a character (let's say Eliza) and as I'm writing I might think, "No, actually I think I want to use another name like Macy instead." That then makes me go back and I lose my train of thought. 
The reason I really want to keep up with writing is because I just feel it's a more productive thing to do than go online when I'm done with homework/studying, and it's a skill I just don't want to lose because when I . have a firm idea, I love it. I still read books as well, but miss when I was younger and just wrote things without overthinking. 
Has anyone experienced problems with overthinking when writing? I hope I'm making sense! 
Vejas