Your NOSTR pubkey is tied to your seed phrase, but not your username. There's no uniqueness constraints on usernames yet, that's something we need to fix sometime soon.
If you lose your seed, your account is gone, but not the name.
Discussion
Pressed "like" a few times, got a tx failed toast but no meaningful error.... scanning console I find "txn-mempool-conflict" meaning we're attempting to double spend some utxos somewhere