Only 24 or so hours after an offer, yes, withdraw it. Nobody has spent any money yet. The seller may be disappointed, but they haven’t lost anything yet, except an offer that may or may not have turned in to a sale.
Don’t worry about the estate agent, they are akin to the scum on the dog turd on a tramps boot.
Boot on the other foot, seller excepts an offer, buyer starts the process, searches, solicitors etc. costing the buyer, about to sign contracts, seller dicides to take the house off the market. Buyer £1000 out of pocket. 3 months later the house is back on the market. She would have been happy to wait.
Happened to my SiL. I did offer the use of my Bombers and my full bladder.