Kent captain James Tredwell says they need a vast improvement following their 10-wicket defeat to Worcestershire.
Kent lost the County Championship game inside two days after being bowled out for 63 in their second innings.
BBC Radio Kent:
"It just wasn't good enough. It certainly wasn't a 60-odd all out wicket.
"If people don't realise that, they're not in the right place. Mentally, there is nothing worse than a defeat like this. We need to turn it around."
He added: "I am sure everyone is hurting as much as me.
"We can't mull over it for too long. Everyone has got to be honest with themselves.
"As long as we can come back stronger for the Essex game we can hopefully learn from the experience."
Kent sit bottom of the Division Two table after two defeats and two draws from their opening four matches.
Tredwell has backed the county's batsmen to put in better performances when they face Essex at Chelmsford, starting on Wednesday.
"Some people go out and practise for hour upon hour and others like to get away from cricket and free their mind," Tredwell continued.
"We've shown real character in one-day games and even showed mettle in the first two four-day games. If we let it eat us away we will not be in a great place.
"Hopefully we come on a good wicket at Essex - that's what the batsmen are looking for.
"I am sure there are big scores around the corner for everyone.
"We have all got runs at various points. We just need to put it all together."