My manager is very impatient and often criticises me. I cant take criticism well and have a low threshold of stress. What can I do to get stronger (to cope) on my own and without changing her at all?

Simply speak to her. I had something like this happen and I just spoke to my manager about how I feel at work, about my work ethics and how to make things better for everyone.

There is a difference between constructive criticism and berating someone. I'd suggest you speak with your manager about how you'd like to receive feedback on your job performance. If you can I'd recommend taking short periodic breaks to decompress. Go for a walk, read, take a nap. Whatever you find relaxing.

keep calm and be patient and see things from your manager side and understand and be supportive to your manager

No one will ever change anyone; we can only change ourselves. As far as learning to cope, try doing some self-reflection, understanding your stress and criticism issues. Once you do that, you may be able to change those patterns and learn better coping skills.

In my experience in such condition, the best situation will be to switch your job. If that is not possible then change your department within the same organization. If you have to be with your current bose, then you can try to look further as to why your bose feels irritated all time and see if you can do something to address your boss's problem.

well, you know that she is like that so don't take her comments too personally. What helps me is to rephrase it in my head on what I can do to better myself.

That sounds really tough to manage. I'm so sorry that you are going through this. Getting strong doesn't happen overnight and will take time. I think it is important to ask ourselves, why am I sensitive to this? Have people been cruel in the past or impatient with you? Sometimes people are impatient and at times uncaring. We shouldn't blame ourselves but try to understand what is driving this person, impatient person, as well. Sometimes the people that abuse or rude need help to understand that is what they are doing.

In order to cope, you have to understand that it isn't your fault that she is impatient. To get stronger, you have to learn from your experiences with your boss, and get strength from knowing that you are doing your best, even when other people don't understand that.

Reach out to your manager to see what improvements there might be with regard to work ethics, quality assurance, or something that would ultimately further you both in the workplace. There is always common ground.

All you need to do is keep your calm, do breathing exercises. Listen to peaceful musics. All will be good