You're confused if you think being "in" a "simulation" makes sense and is something that could possibly be true or false. Quick question, what would happen if our supposed superuniverse had two computers running the exact same simulation? Which one are we "in"? What do we experience if that one turns off?
A simulation is a mathematical abstraction. Math doesn't need to be "instantiated" (really, it can't be) to be true. If you're going to believe that computations can produce conscious experience, a prerequisite for considering a simulation argument, can you explain when the experience of 1 being added to 1 happens, and when it doesn't happen? If you write down the equation using Arabic numerals, does the feeling of being 1 and being incremented flicker into existence for a moment? Or when you read the equation and think about what it means? What if you slide some beads on an abacus? What if a child who doesn't know how to interpret an abacus moves some beads at random, occasionally doing the motion that abacus users interpret as 1+1?
And imagine you are the one being incremented. Can you tell if you're in the abacus, the pebbles, the human mind, the written equation? An array of capacitors? Or would it simply be the case that your experience consists of the relevant mathematical relations, to which the implementation details are irrelevant?
(If only more complex computations produce experience because of [insert "emergence" or your other favorite voodoo], swap in such a computation. I picked a simple one that happens all the time, but other computations are not a different kind of thing than simple addition.)