don't have the game, but i was under the impression you could walk over to the final boss fight in 15 minutes. are you maybe doing some min maxing to avoid that fight?
I mean, sure, they're probably crazy good, but i doubt you're 30x worse than they are. Watch a video or two. I don't think you'll set a record or anything, but i bet you'll be able to finish the game real fast.
You can't expect to do a speed run on your first play through without following a guide, and if you do that what's the point in even playing it? Unless beating games as fast as humanly possible is your thing.
[0] http://kotaku.com/far-cry-4-has-a-hidden-bad-ending-16589899...