If you prep to write in September you will probably use up all the recent PTs getting ready for it. If that's the case, when you study for December, you won't have any new ones to analyze your thinking. You won't know if you improved your skills or if your score improves because you've already seen the tests. I think this is very important.

I think you may want to consider changing your test date. I know it's a disappointing decision to make because I came to the same realization and changed my date from September to February already.

I have the same problem.

I warm up with LR questions I've already done so when I start a new LR section I havent seen before, it doesn't feel like the first one. My mind is prepped to interpret the language the writers use.

I think the panic results from nerves brought in by going into answering questions cold.

I haven't done any full length PTs yet so I don't know if it would work in that situation.

Hope this helps