Marilyn locked himself away in his mother's living room for 15 years.
The androgynous 53-year-old British singer - whose real name is Peter Robinson - has revealed he went through a nervous breakdown in 1989 and moved back to his mother's home in Norfolk, East England, which saw him only leave the house to buy drugs.
Speaking exclusively to BANG Showbiz, he revealed: "I think I had a nervous breakdown really. I made the conscious decision, I'm going to go to my mum's and I left my flat and everything in it. My career, friends, relationships, everything. I just went f**k it.
"That was in 1989. I was sat in room on my own for 15 years, easily.
"In my mum's, I lived in her front room I didn't leave the front room for 15 years, except to go to hospital or to see a dealer if they would come and knock on the window."
Despite taking a dangerous amount of heroin and hitting rock bottom, Marilyn never contemplated taking his own life.
He said: "No, I didn't because I would be dead or already. That is how it was. Why would I be sitting in a room with the curtains drawn. My world reduced to this."
Marilyn said the only thing that made him stop taking narcotics was the effort it took to get the money to pay for them, meeting with dealers and the fact they had no affect on him anymore.
Asked what made him wake up, he said: "Because they didn't work anymore. I'd been doing it for 15 years and it started off alright because it was doing what I wanted it for. Finding the money and who has got the gear. Organising getting it goes on and on and then dealing with the infections of this and that. The whole thing is either getting the money to get it or finding a way to get it. It used to be like a relief, but it had turned from that into an anti-climax."
Marilyn is now back making music and has just released his new single 'Love and Money' - which features Boy George on vocals and was written and produced by the 'Karma Chameleon' hitmaker.
Even when he turned his back on the fame game, Marilyn still sought comfort in music and has always been able to process his feelings through songs.
He said: "Music has always been a massive part of my life. When I was knee high I had a record player and if you had a single, you'd play it all day. My first record was Sonny & Cher's 'I Got You Babe' and I wore the grooves out. I've always used music to wear the arse out of what emotion I was feeling, it's always been a part of me."
Marilyn's song 'Love or Money' is out now.
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