To start with: do not think that you will write a paper in one shot. Writing is a process, and has to be done in phases. There are three main phases of writing, i) Outlining, ii) Drafting, and iii) Editing.
Outlining is the phase when you write in bullets. You do not need to write complete sentences, just phrases are enough. The idea is to write bullets about what you are going to write. Try and fix the structure of the paper, write down the sections and subsections, but inside them there are no sentences, just bullets. Your arguments, and the flow of the arguments are the main thing that you are trying to fix. Once you have a version of the outline, then we iterate on the outline and refine it, until the story is set. It is must easier to iterate on outline, rather than writing, because i) outline is smaller, so you can see and think about all of it at once, and ii) fixing it is much easier than fixing writing.
Drafting: Once the outline is set, then start converting bullets in paragraphs, and complete sentences. We iterate on draft, so that the idea is conveyed as accurately as possible.
Editing is the phase of going over your final draft, and fixing grammatical and sentence construction errors.
As you can see, the most important phase in technical writing is the outlining phase. Once that is fixed, rest is pretty fast.