this is very vague so with out much explanation my first instinct is; Am I?
more of the latter, though i'm apt to phrase it as "I am?"![]()
I doubt that I exist, then affirm that even if I don't, it doesn't matter, then question myself again, etc. etc...
Same.
Most existentialist philosophy for me ends in the acceptance of not knowing. Existence seems real enough that I work from the axiom that it is real. And even if existence isn't real, some substitute and/or simulation of it is real because I'm experiencing it.