Novice biofag here, haven't done anything with my undergrad Molecular Bio degree for 3 years and now try to get into grad school, so my knowledge is both somewhat outdated and extremely rusty. I got into molecular bio because I fear death and want to live forever. Telomere extension is a dead-end from what I can tell (what with all of the cancer), and we don't really know exactly what causes aging, although signs point to it being genetic. Now, CRISPR allows us to edit genes in vivo, although I can't (easily) find documentation as to how long a sequence at a time can be changed.
Here's my crackhead idea:
Let's say we have the thorough genetic (and epigenetic) sequence of a 25-year old. A decade later, at 35, this sequence has changed via both mutations and telomere length. Assuming that aging is a result of genetic change, could the sequence be "repaired" with CRISPR to change the mutations back? How extreme can such treatment go? Would it possible to, with multiple treatments, entirely revert someone's DNA sequence back to an earlier version, like rolling back a software update? I recall the CRISPR insertion mechanism may not be viable for telomere extension but I could be wrong.

I don't want to die