A couple ideas that might help.
1. Get the Always Welcome reward trait and visit someone in the neighborhood where you do most of your searching. You'll be able to cook, sleep, take showers, etc. while you wait for things to spawn.
2. Become a spellcaster and use the Copypasto spell on a Fossil Rock before you Extract Fossil. You can make as many copies as you want and the fossils are still random. I got six different fossils out of 7 copies and I still have the original Fossil Rock.