Unfortunately, it sounds like you deleted it instead of equipping it. There is no way to recover deleted items as once they are gone, they are gone for good and Bungie does not replace lost/deleted/glitched/missing/eaten-by-underwear-gnomes items period.
Please read Bungie articles. It will save you time making a thread that already has an answer.
https://www.bungie.net/en/Help/Article/12211
[quote][b]Bungie does not provide the following services:
[/b]
Restoration of deleted characters
[u]Recovery of dismantled, scrapped, deleted, or otherwise discarded items[/u]
Recovery of mistakenly Infused items
Recovery of items lost due a Character's Postmaster being full
Restoration of access to items or content gained through game sharing
Refunding in-game currencies on accidental purchases
Refunding Silver or transferring Silver between accounts or Destiny releases
Transferring items or characters between platform accounts[/quote]