For me I exist in this temporary state within Existence itself which is permanent but eternally changing as wellDontaskme wrote:
For me I only know I exist when I demand knowledge and all my knowledge comes from memory
I am an infinitesimal part of the eternally changing Existence because I am eternally changing within myself too
I try not to hold on to whatever particular state of mind I am in at any time because even if it is positive it will eventually pass
My own existence within this body will pass too so that is another reason why I try not to hold onto it anymore than is necessary
Already there are parts of my life I cannot remember because memory is fallible so even knowledge of my own existence is temporary
And this is one way in which I am slowly letting go which is good grounding for accepting death when I will have to permanently let go