I really need tips to focus on a difficult task that's urgently due: I feel like I'm being distracted by literally nothing.

I'm sure there's a lot of posts like this here so I'm sorry if I'm repeating other people by making this post. I have this short essay due in couple days for my online class and I really need to get it done today. The problem is the task seems so incredibly stressful that I can't even get past a few sentences. I read on another post that if I reduced the amount of things that could distract me I would be compelled to due my work out of sheer boredom, and that made a lot of sense to me. So I shut off my phone and gave to a family member to hide, I blocked all social media (even reddit, up until I had to unblock it to make this post) and sequestered myself into a small room with as few things in it as possible. I'm not sure if I'm just blowing up the task in my mind, but for some reason it didn't work. This is where the "getting distracted by nothing" part of the title comes into play, because literally I will essentially be distracted from the essay by my thoughts. I'll sit down to do the essay, and I'll write the thesis, but then I'll worry about if the thesis is good enough and pace around the room trying to make it better, but eventually one thought will lead to another and somehow I'm completely off topic to where I originally started and I'm not even working on the thesis anymore! It's genuinely frustrating, because as much as I want to say I've spent the past 4 hours on this essay I've probably REALLY only spent a combined 20 minutes! I just need a way to stop getting up from my laptop every 5 minutes to "think thoughts" and actually concentrate on writing at least something. If this feels like I'm just complaining about being lazy I'm truly sorry, I just feel so exhausted right now but equally stressed that I can't seem to get this simple essay done, and so I've come to Reddit to escape the echo chamber in my own head.