You have this great, easily accessible, and large thing called the vault. I don’t know if you’ve heard of it but it has the twilight garrison logo and it’s right next to the cryptarch and the gunsmith. On the other hand, if you accidentally deleted a weapon just grind for it again. Yes it does suck but it’s a game so just keep playing it. The other day I saw Gladd accidentally delete a god roll weapon. His reaction? “Well -blam!-, I’ll get another one in the future.” And if you don’t, it’s fine just move on and find another great weapon.