In a recent patch they added the starry effect that raises from items on the ground to the spear. Still doesnt guarantee you will find it but try looking around about 20 meters from your character as you run around instead of right in front of you. The whole cant see forest through the trees idea. On my spear guy I have one "main" spear that I use for melee, and three others for throwing all on the hotbar. The main being currently upgraded for the biom im on and the others either flint or later on fang. Since I have lost spears in the past I try not to throw my main. I hear ya though...... its frustrating. I wish you the best of luck!