Late Friends star Matthew Perry was so committed to sobriety, he was reluctant to drink Diet Coke because of the caffeine and refused even to touch the drink menu during lunch the day before he died, DailyMail.com has exclusively learned.

Perry, who was just 54, was found dead last Saturday in the hot tub at his $6million Pacific Palisades cottage – sparking an outpouring of grief from friends and fans.

Now, in an exclusive interview with DailyMail.com, the woman photographed lunching with him at the Hotel Bel-Air a day earlier has described how chipper Perry had looked healthy and happy and had even quit smoking.

Model and entertainment reporter Athenna Crosby, 25, also told how Perry had been full of plans for the future and dreamed of making an autobiographical movie about his life with Zac Efron in the title role while he would make a cameo appearance as a therapist.

Speaking in an exclusive interview with DailyMail.com, the glamorous brunette said: ‘I don’t think he had any desire to get back into drugs and alcohol.

‘I think he was so proud to finally be over that hump because he openly struggled with addiction for decades, and he was in and out of rehab as recently as the last couple of years.

‘He was relieved that he finally felt it was behind him, and he was trying to do everything to fight that.

‘While we were having lunch, he refused to touch the drink menu. He was saying that he’s gotten really into fitness and pickleball and he wants to get all his friends into it.

‘I think he was really serious about revamping himself into a whole new man.’

She added: ‘He was a little shy to order a Diet Coke because that’s caffeine, and it’s one more thing that some people might struggle with.

‘But then eventually he said, ‘I’m actually doing really good, and this is just a little treat to myself’.

‘He was concerned about anything that could compromise his health. That’s something that he took really, really seriously.’

Perry had spoken openly about his battle with booze and drugs in recent years and, in his autobiography Friends, Lovers, and the Big Terrible Thing, described how he had either been on narcotics or alcohol or both throughout his decade as Chandler Bing on the smash hit show.

He described being driven to and from rehab while filming the scenes where his character married best friend Monica, played by Courteney Cox, and said co-star Jennifer Aniston had confronted him about his addictions – telling him the whole cast could smell alcohol on him.

But, after spending $9m on multiple stints in rehab and enduring a health scare aged 49 when – due to his drug habit – his colon exploded leaving him in a coma, Perry said he had been sober for several years when he died last weekend.

Police who attended the scene of his death found no illegal drugs at his home while medics found no trace of meth or fentanyl in his system during an autopsy.

A toxicology report is pending as is a final verdict on his cause of death.

Athenna, who met the actor ‘at the start of fall’ when they were introduced by a mutual friend, said the lunch they shared was the first they had enjoyed.

She told how Perry had invited her for a meal to discuss her career and said he gave her advice on how to handle fame and warned her to be careful with the pain meds she will get during an upcoming wisdom tooth operation – saying that those drugs were his gateway into addiction.

She told DailyMail.com: ‘That was the first lunch that I had had with him. I had met him before in person and talked to him a little bit, but that was really the first lunch that I had had with him.

‘It’s just so crazy that he happened to pass away the next day because I did not know him that well, and I happened to be getting to know him while we were at lunch.

‘I was asking him questions about himself, and he was so open. He was such an open book telling me so many different things. It felt like I had known him for so long, and he really just made the experience very positive.

‘I thought, ‘oh, great. This is somebody that I can have in my life who is a really good person that I can trust’. And then he’s gone the next day.’

Athenna said she discovered Perry had passed away after seeing a news report and told DailyMail.com she is devastated that he never got the chance to put his plans into action.

She said: ‘He wanted to start his foundation to help people struggling with substance abuse, whether alcohol or drug addiction.

‘He also really wanted to have a movie made about his life. He was an actor and he wanted to get back into it.

‘He wanted to have Zac Efron play him and he wanted to make a cameo as a counselor or a therapist, sort of giving advice to the character playing him.

‘He had a very clear idea in his mind of how he was going to take this circumstance and transform it into a story and use the medium of storytelling to reach people and really use his talents for that.

‘I really hope that those closer to him and his contemporaries and the industry can make that happen.’

The 25-year-old says she didn’t know whether she woul be invited to his funeral but said she will always remember his kindness and that he was prepared to make time to help people right until the very end.

‘Even though he struggled, that did not stop him from being an amazingly generous and nice person,’ Athenna said.

‘It just goes to show that even people who are rich and famous can struggle with loneliness or substance abuse, but at the end of the day, if you can’t use your fame and popularity to help others, what legacy do you really leave?

‘I think he understood that very, very well. He knew that he needed to make this a moment much bigger than him.

‘So now the challenge is for us to learn from this, do better, be better, make better decisions, and really care for the ones that we love.’