I have been awake for 48 hours, I am on Mirtrazapine but I can’t keep track of when to take it and I am so tired but hours in a dark room is hopeless

What am I meant to do I have spent my entire day outside in the sun going for jogs in an attempt to exhaust myself, my diet is really balanced and my routine isn’t out of whack but for the better part of 6 months i’ve been really really suffering with insomnia and I can’t cope anymore I am exhausted.