mempool.space's accelerator needs an account and it need to be activated by them,
mine which was registered about a month ago is still in their "waiting list".
So either they don't have the connections yet, or they don't want to earn money? That's weird for such a service.
Some people claim that they have an account with access after becoming a sponsor so it must be working.
But reason for the waitlist is unknown.
I discussed this with OP, but he doesn't feel confident handling private keys and manually doing this in another wallet. Wallet B can't do anything.
Okay, so one of his option is to wait for the average fee rate to drop below 44sat/vB.
Last week, transactions with even lower fee rate than that got confirmed so he just needs to be patient.
Or if he want it to confirm faster, paying for a legit accelerator services will be expensive for 1000vB+200vB (
approx) transactions.
He will have to pay about $500 to those pools.