So I'm trying to make a spear that is a throwable item, and currently when I pick it up after throwing it, all nbt data is lost including enchantments, name, etc and I was wondering how I would go about moving the nbt from the item to the entity and back to the item. I already have the spear throwable and working.

Thx in advance :D

You can save the itemstack in the entity (ItemStack.write() ItemStack.read() or something like that to store the data), and use it when needed.