The West Ham captain received his marching orders twice in the space of a month, in the 4-1 defeat at Liverpool on December 7 and the 2-1 setback at fellow Premier League strugglers Fulham on New Year's Day.
Nolan's dismissals left manager Sam Allardyce fuming given his squad has been deprived of the likes of striker Andy Carroll and winger Ricardo Vaz Te for large parts of the season.
The 31-year-old returns from suspension for the second leg of the League Cup semi-final against Manchester City on Tuesday, with West Ham facing a near-impossible task in overturning a 6-0 defeat from the first encounter.
But Nolan is itching to start making amends for his misdemeanours.
"The last few weeks have been among the most difficult of my career - certainly on a par with when I joined Newcastle and they got relegated," he told The Evening Standard.
"That was a tough time but I came through it and when I go back up there now, they treat me well, I get respect because they know what I'm about. I'm a fighter.
"What's happened to me over the last month was very out of character. I've never been through anything like that before - but I have now and I'm hoping to prove, by the end of the season, that I've come through it.
"Things have been made easier by the support I've had from my family, friends and Lee Richardson, the club psychologist.
"It's at times like this you appreciate who is next to you, who is around you, and my support system is fantastic."
