Henman led 4-2 in the final set but could not close out the match
Tim Henman will head to the Nottingham Open next week desperate to revive his abysmal form before Wimbledon begins.
He admits he desperately needs a win to boost his form, which has brought just one win on tour all year.
"I have been doing a lot of losing recently and I've got to try and break through," he said after defeat to Marin Cilic at the Artois Championships.
"I'd love it if there was one specific magic ingredient I could change, but it doesn't exist."
Henman last played in Nottingham in 2000 when he lost in the first round to Jonas Bjorkman and has been handed a wildcard for this year's event.
The 32-year-old has reached the semi-finals at Wimbledon four times, most recently in 2002. The 2007 tournament starts on 25 June.
Henman, who has been fighting a stomach bug, was 4-2 up in the final set on Tuesday but ran out of steam against the Croatian wildcard, who is listed 56 places below Henman at 110 in the world rankings.
I've played long enough to understand I am going through a difficult spell right now and the only way to come through it is working hard
It was the first career win on grass for the 18-year-old Cilic but a disastrous result for Henman.
He has been hampered by a knee injury and a long-term back problem this season and was looking to get some competitive game-time under his belt with Wimbledon just a fortnight away.
"I'm in a rut right now and I've lost a lot of matches. I would love to play horrendously and win," he said.
"I don't want to keep hitting the ball well and losing. People talk about getting on a roll, when winning becomes a habit, but the same is true with losing.
Henman has been given a wildcard entry for Nottingham, with tournament director Patrick Hughesman saying: "Tim is a truly world-class player who is certain to thrill Nottingham's packed centre court."
The player admitted he is negotiating one of the trickiest spells of his career and insists his fortunes will only improve with hard work.
"I think first and foremost it's a confidence thing. Obviously not playing enough matches and not winning them doesn't help," he said.
"It's the same in any sport - if you are struggling with confidence you have to keep working at it.
"I can't hide from the fact it is very frustrating. I've played long enough to understand I am going through a difficult spell right now and the only way to come through it is working hard."
Henman had to save a break point in the first game of the match but survived.
He soon established a 4-1 lead but Cilic broke back in the seventh game at the third opportunity and the set went to a tie-break.