Your current state of mind likely depends on the extent to which you've prepared for your exams. Going by previous threads, I would believe you are a student that works very hard and does her best in order to ensure she's fully prepared for her exams and this is something that has, of course, manifested itself in your great marks and ranks. Being stressed about the fact that you have 5 exams this coming week can be seen as a positive thing in the sense that it shows that you care about this particular stage in your final year of school. Of course, this doesn't mean that experiencing two breakdowns a week before your trial exams is beneficial (in terms of performance) or healthy. I think that, in your particular case, there are 2 important things you should consider and attempt (if possible):
- Ensure you are ready to sit your trial exams in terms of your knowledge of relevant content across all of your subjects. This factor is very important because having doubt (not being entirely sure of) in one's preparations can cause some sort of discomfort and possibly high levels of stress, similar to what you're currently experiencing. Basically, people may feel uneasy when it comes to important aspects of their life that are unknown to them. The only difference in your case is that you can indeed determine whether you've prepared enough for your exams, through your marks in multiple past exam papers for example.
- Focus on eliminating any form of stress in a more direct manner. As I mentioned above, being certain that your preparations are sufficient may relieve you in that regard. In terms of addressing stress directly, simply talking to someone can go a long way towards relieving yourself of stress or anxiety. There are also other things you might be able to do that can contribute to lower stress levels, such as managing the time you have left in a way that allows you not only to be 100% sure that you're ready for your exams, but also to change to a more relaxed mindset, which you can achieve by practising any hobbies, taking breaks and even sleeping when time permits.
I hope this helps! Best of luck with your trial exams!