Anyone else have such a problem with starting WIPs

I don't know what it is, but every time I go to write a short one shot, it always ends up multi chapters, and then I have so many WIPs i get overwhelmed by how many and I just want to start another one and never finish

I have 53 works, and only 29 are complete. I'm currently actively working on 7 WIPs, but omfg I end up just wanting to start something else because I can't settle down to write them

The thing is, I get so obsessed by one story to the point I'm churning out 10k chapters at least once a week, then I get fixated on something new and it keeps happening

From now on I'm going to try writing fics in full before starting to post

Does anyone have any other tips on what to do?