Welcome to Bitcoin. The “balances” in Bitcoin are actually explicitly tracked bits and pieces. You can think of it akin to the coins and bills of cash: when someone sends bitcoins, the transaction explicitly states which coins or bills get spent, and describes which new ones to create. We call these bits of bitcoin unspent transaction outputs (UTXOs). In most Bitcoin transactions, the UTXOs you have in your wallet will not perfectly fit the amount you are trying to pay. In that case, your wallet software will automatically create a new UTXO that sends the remainder back to yourself. Imagine if you go to the pub and pay for a 3£ pint with a 10£ bill. The bartender gives you 7£ change. In Bitcoin, the 10£ would be you spending a UTXO from a previous transaction as an input to your new transaction. The transaction input consumes the 10£ and the transaction then creates two new UTXO, one of 3£ for the bartender and one of 7£ for yourself.
What I’m trying to get at is, that in most transactions you will pay the receiver and yourself: in order to return the remainder as change to yourself. I am wondering whether that’s what you are seeing in this transaction.
If you in fact only paid yourself, you’re fine as well. You may have split your bitcoin funds into two UTXOs now, but your wallet is capable of using multiple of them in a transaction together.