One week left for my exam. How to utilise this fully?

You have a week left for the test so until and unless you are fine with pushing back the date, you don't have much time to go back to basics and work on your problem solving techniques. In that case, I would suggest you the following in Quant:
You said that when you come across an unknown pattern, you freeze and waste time. Also, you are usually short on time and have to guess on the last few questions. So then, you should guess on the questions which have an unknown pattern. When you come across such a question in the test (assuming there are not more than 4-5 such questions), just guess on it and move on. It gives you the comfort of knowing that you don't have to solve every question - if you feel yourself going cold while reading the question, just guess - don't waste time. Anyway you guess on the last few questions. This way you wouldn't have to on 4-5 questions in a row. You will have enough time to work on the last few questions too.

As for CR, I suggest you to check out the various question types from our blog: https://www.gmatclub.com/forum/veritas-prep-resource-links-no-longer-available-399979.html#/categor ... +reasoning
There isn't a lot to it. You can get a good grip on CR in a few hours. Once you understand it, you can handle most questions easily. If your RC is not a problem, it means your reading skills are fine and hence CR shouldn't be a problem too.

Taking a mock every other day is a bad idea. You tire yourself out and don't learn anything from it. The evaluation and analysis post the test is what adds real value to your competence. The time spent in taking the test itself doesn't make a lot of difference. Point is, from today till your test day, don't take any practice test. If you must, take one today or tomorrow and that's it.

Hi MathildaBagshot,

Although you have not stated your specific score goal, if it's 700+, then I think that you should consider pushing back your Test Date.

Test Day is a rather specific 'event' - the details are specific and they matter, so you have to train as best as you can for all of them. The more realistic you can make your CATs, the more likely the score results are to be accurate. The more you deviate, the more "inflated" your scores can become. From what you've described, you've been taking your CATs in ways that do NOT match up with what you'll face on Test Day. By skipping sections, taking the CATs at home, taking them at a different time of day, etc., you weren't properly training for the FULL GMAT 'experience.'

Thankfully, this is a relatively easy set of problems to fix. The big question now is "how long will it take you to properly get 'used to' taking the full GMAT in a way that properly mirrors Test Day?" You'll certainly need a new set of practice CATs to work with and you have to put in the necessary time to train your brain (and body) for the FULL GMAT.

1) What is your score goal?
2) Do you have the flexibility to push back your Test Date (even if it's just a few weeks)?

GMAT assassins aren't born, they're made,
Rich