I am so sorry you are struggling. I also have CKD stage 4 for a while after my surgeries for cancer but now improved to stage 3.
I know it can be frightening to face a chronic illness. That us a normal reaction for most people. I have been stage 3 for about four years and my kidney function fluctuates a little but is holding it own pretty much.
I would encourage you to focus on the specific questions for your nephrologist ...
- are there underlying health issues that created this that I need to address
- what specific things do I need to do to help my kidneys remain stable
Write down all your questions so that you have them for the Dr.
My main goals are five fold
1 - focus on just to live my life well, to be present in every moment and enjoy the things important to me . Remove negative stressor that I can remove as stress is hard on the body . I refuse to focus every moment on illness. I purposely turn my thoughts to something else... I use my faith a lot here to keep my my mind focused positively. Getting out in nature, grounding myself with things important to me
2- eat healthy food , regularly
3- get rest. Sleep is important in healing our body
4- be well hydrated- limit caffeine and alcohol. No sodas . All hard on kidneys
5- build my faith foundation

It might be helpful for you to find someone that you can talk to about all of your fears and emotions. It could be a close friend, someone in your faith community, a Chaplain at the hospital, or even a therapist for a period of time. There are also support groups through various kidney foundations and networks or your local medical center.
Just sharing your fears may help you process and cope with them better. I am wishing you the best and hoping you are doing better !