iCloud back up items lost

So my company give me a new iPad for work so I backed it up off my iphone. I didn’t want personal stuff on there like photos etc. So I deleted all photos off the iPad not knowing it would delete everything off my phone as well. I’ve erased my phone and done a back up off the 6th march. But the restore hasn’t got all photos from 2016 backwards. Also all missing recent holiday photos and videos can I get these all back maybes 2000+ photos