And i can not find a software that keeps inventory on my leftovers sheets and automatically do the nesting on the sheets from inventory
This sounds nice, but at the same time is wholly dependent on the physical organization of drops. I'm probably a pessimist here, as I cut my teeth dealing with a router and drops, and while I kept a stash of semi significant drops, I'd only pull on that stash if we were in a time crunch, or if someone was trying to sell something cheaper by saying they used 'scrap' material as opposed to 'new'.