Overcome with jealousy, the singer downed an ENTIRE bottle of pills in a desperate bid to block out the pain.
But, just like his relationship with the catwalk queen, things didn't work out for Pete, who failed in the suicide bid after he was violently sick.
Despite his despair over Kate, the Babyshambles frontman made it out of Clouds House clinic in Wiltshire this week — after apparently six weeks OFF the drugs.
And, as our pictures show, 28-year-old Pete has piled on the pounds during his latest stint in rehab.
The troubled star's minder, Johnny "Headlock" Jeannevol told us: "Pete's been really wound up over Kate showing off her new man.
"He saw an opportunity to take an overdose and took it. He told me he didn't know what the pills were but thought ‘f*** it' and took them all."
"He doesn't care what drugs do to him—in fact, he likes finding out."
Another pal of the rocker, who asked not to be named, said: "Pete was so low during rehab his legal team considered sectioning him under the Mental Health Act in order to get him the treatment he needed.
"It was touch and go with Pete for a while but he pulled through in the end."
Pete's suicide bid came just weeks after it emerged Kate, 33, was dating Kills singer Jamie Hince, 39.
Johnny — who faces a possible police probe into the death of a man at a party attended by Doherty — also revealed that Kate was on the phone regularly while he was in rehab.
He recalled: "To begin with Kate was ringing him up all the time, concerned for his well-being.
"But when Pete started to quiz her about the new guy, she was evasive and it got to him. She messed with his head.
"But now he's out and happy. He's trying to keep off the drugs and needs his own space.
"Hopefully Kate will stay away this time but she can't help herself. She's obsessed with him."
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