It's okay to question everything every now and then. Camus has written brilliantly about your frame of mind. Once in the book "The Stranger" which describes you...and another in a more philosophical work called "The Myth of Sisyphus" A person from Greek Mythology who was condemned by the gods to roll a boulder up the hill every day, only to have it drop at the base when he was done.
All our experience Squirrels does not provide us with an answer to "Why?" When you ask "Why" what you are really asking is "How am I immortal?"
Well...we are not. And what we do today...will matter absolutely nothing in the next 2 million years and completely forgotten. Fine. If we can't live with meaning at least we can live with dignity. Life is a debt. The men of 4,000 years ago kept spearing the fish, and climbing the trees, and making the tools, and kept grunting and F*cking their women...and because they didn't question but did it, or maybe did it in spite of their questions you and I are now alive. So pay the debt if you wish and know that as YOU are getting better...a part of you is helping improve MANKIND in a small, very very minute way...and though you are MORTAL the human race may well never be.
When I was 5 years old I locked myself up in the bathroom and thought of all the people I loved best dying, one after another...I cried for what seemed like hours...and then the most terrifying thought hit me: "I, the Danton that everybody should love and that I loved most, I...was Mortal too. How could my hands which were so perfect stop moving at some point...how could my eyes not see anymore...how could my feet not have any blood and disintegrate like pieces of charcoal" I couldn't help it...I cried and cried just sitting there on the toilet and my Mom kept knocking on the door to make sure I was Okay and when I shared with her what was wrong with me she broke through and Smacked me hard...the slap still stings to this day. I am 35 now...not much has changed...but the moral of the story is we all need a slap every now and then.
Set up some goals to grow...and shake it off man. And keep shaking it off for the rest of your life...because your life will not provide answers...not on this...not on this...the most important of all.