The BTC has not left your wallet, it's still an unconfirmed transaction. Your wallet just won't let you try and spend it again while it knows about that transaction. The nodes on the network each keep their own version of the mempool which contains all the unconfirmed transactions they know about. How long they keep transactions before dropping them is configurable so they are not all the same. Once it starts to get dropped from nodes you will have a good chance that your wallet will no longers see it and you will be able to send another transaction. I use Electrum and when it has happened to me in the past it was about 3 days, although it could take longer. Another thing if you can next time is to always use the replace fee opt-in if your wallet supports it, then you don't have to wait.