Hi Sam,
I took the GRE just a few months ago and did fairly well, so here's a bit of general advice:
First of all, breathe. When it was down to 2 weeks for me, I prioritized staying healthy over studying and tried to fix my sleep habits so I could be awake (8am exam). It's a mental test, so you really have to put yourself in the right mental state.
You made flash cards already - great! Keep reviewing a few words a day until they really stick. I would recommend looking at the vocab you missed on the practice exam and making a flashcard for every answer choice you did not know. After enough practice exams, you should have most of the common words covered.
One thing that stood out to me was that you said you READ the word list and READ the quant section. Please, please, do yourself a favor and avoid studying like that when possible. It's better than nothing if you're occupied, but if you can set aside time to study, it is much better to study actively. Especially on the quant section, this means doing problems. For verbal, you can just make sure to review your flashcards (so you can't see the definitions right away, and have to think about it). It's much more mentally taxing, but trust me, it is well worth it.
1) I can't speak for every test, but you should definitely review some algebra, percents/ratios, and maybe some combinatorics. If it's been a while since you've done math, make sure to recall some nice rules to save you time, like divisibility rules, or things like x% of y is always y% of x. Simple geometry such as triangles would also be helpful.
2) It seems counterintuitive, but outlining my essays really helped me speed up my time. I would write down my main points, then start writing my essay in the space around them. Remember that GRE graders do not care about what you may have learned in elementary school about stating an introduction/conclusion and restating all your points. Just jump straight to the body, with maybe a few short sentences to tie things together if you feel the need. (Transitions can definitely only help).
3) Reading comp can be pretty variable in content and structure, but it helped for me to jot down a one-sentence summary of what I read as I read each paragraph to make sure I was actively reading, since most of the reading you do day to day you probably don't need to pay that close attention to. Then, when I read the questions, I would block out the answer choices, try to come up with my own answer based on the text, and see if it matched any of the answer choices.
If you need any more specific advice, help with math questions, or critique of your essays I would be glad to help - send me a PM. Best of luck!