James DeGale has revealed his mother, Diane, talked him out of quitting boxing when depression threatened to envelop the frustrated Olympic gold medallist after six years as a professional. On Thursday his spirits were considerably lifted after he committed to a change in career by leaving his promoter Mick Hennessy to join Eddie Hearn's Matchroom stable, and he finds himself within one win of a world title fight, possibly against George Groves, with whom he has shared a mutual loathing since they were teenagers.

DeGale will box on the undercard of Groves's rematch with the WBA and IBF super-middleweight champion Carl Froch at Wembley on 31 May. If he beats the undefeated American Brandon Gonzáles – who shares a trainer with Amir Khan and Andre Ward – in what has been sanctioned as an IBF final eliminator, he will challenge the winner of Froch-Groves in October.

Hearn sees that fight as another potential blockbuster to follow the 80,000-capacity Wembley show. Hennessy, meanwhile, did not add to his statement of Wednesday when he contended he has a valid contract with DeGale, and was considering legal action.

"The fighting is easy, to be honest," DeGale said, as he described his deteriorating relationship with Hennessy, after two years and six fights together. "But I was in a dark place. Boxing has been my life since I was 10. When you're not happy doing your job, it's hard work, right? About six months ago I went, 'Mum, I've got two properties, I've got a nice car, I've got a pension, so fuck this boxing. I'll go and earn £1,000 a week doing personal training.' I was doing the numbers to give up. I was this close. She said, 'Don't be stupid. What's wrong with you?' But that's how I felt. My career was going nowhere. People were overtaking me that I was well ahead of. I boxed for the British title in my ninth fight. I was European champion when I left Frank Warren [to join Hennessy in 2012]. I thought, in the next couple of fights, I'll fight for the world title. It didn't happen."

"Now, the IBF have given me a straight route. So I'm boxing [the winner] in October if I get past Gonzáles, who's actually a good fighter. Potentially there's some crazy money to be made, some crazy fights to be made. That's what drives me on. This is going to be fun now."

DeGale said of Groves, "I still can't stand him and he can't stand me. Groves is a fool. Groves is a fake. I will never let him belittle me like he's done with Carl Froch. That's a 50-50 fight but the way he started last time, Groves was hitting Froch for fun. It was embarrassing.

"I've been saying for years, Froch is an easy fight, chin's up in the air, feet are all over the place, technically terrible. But he's tough, he's strong, he's fit for 12 rounds, he comes on strong the last few rounds."

DeGale added: "Groves is a bit more difficult because he can switch it up a bit more. But he'll hold the centre of the ring. He's not scared of Froch.

"I think it's going to be another good fight. I just hope Carl Froch is better. He took him lightly last time. I've never seen him as bad. So everyone thought, this guy [Groves] unbelievable."

If he can't pick between them, there's little doubt who James DeGale would rather fight for the world title.