I've got myself in a bit of a pickle. I withdrew some Bitcoin from a service last month, however they sent it with a really low fee (40 sat/byte), so it is still pending and is unconfirmed. I understand Child Pays for Parent, but the inputs of this transaction, around five levels deep, are also unconfirmed. I asked them to resend the transactions with a higher fee, but that might take a while.
Today I sent a transaction from Blockchain info. I used a reasonable fee for today (250 sat/byte), so normally it would be confirmed within a few hours. However the transaction used the unconfirmed transaction as an input, so that transaction would need to be confirmed first, which probably isn't going to happen.
As I understand if I send a new transaction, with a higher fee, I can reuse the (confirmed) inputs and that transaction will be accepted, then the transaction with the unconfirmed input will be abandoned. I've tried using Electrum to resent the transaction with a higher fee (and making sure it doesn't use the unconfirmed inputs), however it just says an error saying my balance is too low, as it treats the unconfirmed transaction as spent.
Are there any wallets (preferably that don't require downloading the whole blockchain) that would allow me to create a transaction to work around this?