Id just kill myself because in my book there is NO way to fix that.. You cant kill all of those zombies! And if u try u would die in the procces so i would want to die peacefully, and not die with a back ache from attempting to kill them. Really there is NO point because it is only YOU, the only person against endless zombies.. Unless you want to find a cure wich would take too long.... The you are FUCKED because you cant rebuild mankind if only you survive!
I would have no way of knowing that I was truly the last person on earth, so I would spend my time searching for others. Killing what I had to but mostly keeping hidden and moving quietly through the country, stopping in cities and towns only to search for survivors.
i'd be like "screw it, kill them all anyway". and i would try to film myself doing it, maybe as a documentary for future people to enjoy. in the meantime study and find some way to reproduce. no point making a really long action packed film if not one will be around to see it.
I dont think I would ever come to an agreement I was the "Only" living person. I would have to keep hope alive and think out of all the remote locations/underground bunkers and labs, and all the countries across the globe someone somewhere would be alive. You would never know if you were truly the last one alive, that would be the strength to carry on...and if you were, then you wouldnt have to listen to people complain and bitch anymore. Just set up a movie theater with some video games and sit back and chill. As long as animals were alive. Most animals are more fun to be around than people.