By Alan Baldwin

LONDON (Reuters) - The first time Damon Hill visited Suzuka for the Japanese Formula One Grand Prix, the circuit hotel registered him as 'Demon'. The 1996 world champion could laugh that one off, at least.

Other demons -- grief, anger, self-doubt and deep depression among them -- have been harder to brush aside over the years, as he reveals in a frank autobiography ('Watching the Wheels') published this month.

It is a book Hill could not have written when he retired in 1999 and that has required the passing of time, and some years of therapy, to overcome the inner conflict and reach an understanding of who he really is.

"Formula One is about not needing help," the 55-year-old told Reuters before heading to Singapore for Sunday's grand prix.

"It's about everyone being so good that they've not got a crack in their armor at all, anywhere. That's why you keep trying to carry that load. And eventually you just can't get it off the ground."

For Hill, whose double world champion father Graham died in a 1975 plane crash that had cataclysmic consequences for the family fortunes, the full realization that he needed help came only after he hung up his helmet.

"It became too much by the end of my career and I needed to sort myself out. When I stopped, I thought the problem was being in F1. But it wasn't," he said. "It was to do with more issues than that."

Eventually, he rang a family friend who had trained as a therapist after losing her parents in a helicopter crash and asked for help.

"I went and saw someone, sat down and went 'OK, I'm lost'," Hill recalled.

GREAT DUELS

The only son of a world champion to also win the Formula One title, although Nico Rosberg could change that this season, Hill took on Germany's Michael Schumacher in some of the great duels of the 1990s.

At his peak, and in the best car, Hill was a formidable if sometimes under-rated opponent -- a 'tough bastard' in team boss Frank Williams' words. But, unlike the supremely confident Schumacher, he was plagued by uncertainty.

"For most of my life I needed an answer to the big question: am I just a Graham Hill repeat; Graham Hill, Part II? Or am I Damon Hill, Part I?," he says in the book.

"During my career I was always confused about whether I was authentically a racing driver or someone tasked with a mission to complete before I could become my true self."

With German driver Heinz-Harald Frentzen lined up as his replacement at Williams for 1997 even before he had won the title, Hill moved to uncompetitive Arrows -- where he almost won in Hungary -- before two seasons at Jordan.

The book casts a fresh light on Hill's state of mind during those years, and what was going on behind the scenes, without seeking to make excuses or embellish.

"I make it clear. I am not in the same category as (Ayrton) Senna and (Alain) Prost and (Michael) Schumacher and (Lewis) Hamilton," said Hill, who started out racing motorcycles.

"I didn't start at an early age always wanting to be a Formula One driver...I hesitate to say I don't have the natural ability. I think I do. I just don't think I had the training at an early age to get to that level."

Two fatal accidents -- "fault lines, like earthquakes" -- defined Hill's career; that of an adored but often absent father and of Williams team mate Senna at the 1994 San Marino Grand Prix.

On both occasions, Hill felt he was stepping into big shoes with big responsibilities. He has little doubt he would have been a better racing driver had he been a happier person.

By the end, he felt like "an insect in a jar". The fear of dying unexpectedly, like his father, once leaving him curled up in a ball on the bedroom floor at the prospect of flying and leaving his family bereft.

The champion is now in a happier place, enjoying life as a television pundit and with a first class Open University literature degree to his credit.

It is hard to imagine any current F1 driver comparing himself to the Greek hero Telemachus, as he does in the book, or writing so openly and eloquently about such sensitive subjects.

"The whole point with therapy is it's not what other people think it is," he said. "You have to learn to describe it and in a way that other people understand. And then you can get across the bridge.

"It's (like) the caterpillar (said) in 'Alice in Wonderland': ‘Explain yourself’."

(Reporting by Alan Baldwin, editing by Martyn Herman)