I wouldn't be too fearful - It generally feels like Year 10, but just with a different number. So long as you do all your revision, you will be fine!!
One thing I do want to bring up though is your aspiration for all 9's; I don't mean to be rude, or make you more scared than you already are, but you should understand that this is a very ambitious goal, which is very hard to achieve. It is certainly possible to do! But it is also certainly very tough. You should be revising every day for around an hour, consistently. With this goal, you can't neglect ANY subjects, and you need to be very disciplined in your approach to revision. There's no "I don't want to", and there's no "I'll do this subject tomorrow". You do what you're meant to do, and ideally a bit more.
It should also be noted, out of the 553k students who took 7 or more GCSE's this year,
1270 got all 9's. This is 0.2%, and you are competing for a spot in this statistic. This is an immense challenge, and while certainly possible, you need to acknowledge the fact that there's still the possibility you don't get all 9's, similar to 99.8% of the population. I don't want to scare you with this information, or make you feel worse - I want you to think about shifting your goal from getting all 9's to generally getting as high of a grade as possible in your circumstance. If you get all 9's, great! If you don't, great! Because if you're considering this possibility, it's very likely you're already getting very high scores, and so whatever you get will be a good score. Don't beat yourself up if you don't get all 9's, because this is an extremely high bar.
It's of my personal opinion that a 9 is an 8 with an exclamation mark. Nobody really cares which one you get from a practical perspective, and people (Not institutions, people!!) only care about the 9 because of the name and the advertising. Sixth forms certainly don't care. Universities care even less. Someone with all 8's will get the same opportunities as someone with all 9's. Again, getting all 9's is absolutely possible, and you can do it!! But I want you to keep in mind that if you don't, you will be the same person a month later.
The hope of getting all 9's is a hope that serves no real "function" except to be able to say that you did it, and so I wouldn't worry with whether you get it or not. Do the best you can in the exam, and don't worry too hard about the result so long as you know you passed everything strongly. You will be fine. Good luck in your endeavours.
And sidenote, remember to answer every question. Even if you never covered it in class. Even if you have no idea what it means. If you can't answer something confidently because you don't have the knowledge, answer it confidently regardless.