When Megan Ross was 14 years old, she opened some letters her dad had sent her from prison.

In them, Davie Clark explained why he had been absent throughout Megan’s childhood.

He said he was addicted to drugs and did not want her to be around his lifestyle.

“I think that’s probably the first time I understood why he wasn’t in my life,” she said.

“Because for a lot of years I did think: ‘Did he not want me? Did he not love me?’

“But then reading the letters, it made me realise that wasn’t the case at all.”

Megan is now 26. Like her dad, she has spent years addicted to drugs – but they are both now in recovery.

Davie is at the beginning of the process, after relapsing into drug use last year. He wants to get sober and repair his relationship with his daughter.

Megan says, for her own recovery, she cannot be around her dad at the moment.

“That hurts, because he’s my dad and I want to be there for him,” Megan said.

“I can love him from a distance right now, and when he does go back into recovery then we can take the steps to be father and daughter again.

“Now that I’m sober, I want my dad back.”

Addiction runs in Megan’s family.

When she was five, her gran took her to live in Stranraer in south-west Scotland, about two hours’ drive from her home in Glasgow.

She hoped bringing Megan up in a quieter area would keep her safe – but instead, her drug use would spiral out of control in the coastal town.

Megan started taking prescription pain relief medication at the age of 15 after being injured in a car accident.

She started swapping her medication for street valium. That term covers a number of different counterfeit versions of anti-anxiety medications, which make users feel spaced out and relaxed.

Megan began taking more and more, combining the pills with other drugs, such as cocaine.

She was soon involved in a party scene and her life became more and more chaotic.

Street valium was cheap and widely available. Megan could get 100 tablets for £25.

“I was probably taking about 50 valium a day,” she told BBC Scotland’s Disclosure programme.

“It was causing me to lie to my family. It was causing me to fight with the police, doing things that I just wouldn’t do if I was sober.

“It was actually turning me into a horrible, horrible person.”

Megan said pictures taken at the time showed how chaotic her life was.

“You can see it in my face, in my eyes. There’s nobody there. I’m just lifeless inside.”

Megan has now reached a point in her life where she is ready to stop using drugs and has been in recovery for seven months.

Her life is totally different.

She is at college, working towards qualifications she did not get when she was in high school. She is interested in science and hopes to become a lab technician.

Megan said moving from Stranraer to Glasgow had been fundamental in getting her life back on track.

She says there are more support services on hand to help her get off drugs.

Megan has been working with a service called Tomorrow’s Women Glasgow.

It helps women who have complex needs with issues such as addiction, mental health and housing.

Megan has a support worker who has been there for her as she tries to rebuild her life.

“I feel like the luckiest person on earth, and I say that to everybody, because not everybody’s as lucky as me,” she said.

“Not everybody can get out, and I got out because of people I’ve got round me.”

Megan says she cannot be around her dad at this stage in their recoveries, but hopes he will become part of her life again.

Davie is a cocaine and heroin user who spoke about his addiction as part of the BBC Disclosure documentary One More Fix.

He is among the 180 people who have used the UK’s first drug consumption room, which opened in Glasgow in January. After a referral from the staff there, he has moved out of a hostel and into supported accommodation.

Now aged 47, he has been addicted to drugs for more than 20 years.

He first tried heroin inside HMP Barlinnie.

“I felt on top of the world if I’m being honest, because I had never had that feeling of anything doing that to me,” Davie said.

“And from that day, at 21 years old, I couldn’t wait to get out of prison to try it again, to get that buzz.”

As a result of his on/off drug use, he has not been involved in Megan’s life.

He has spent time living on the streets of Glasgow and begging for money.

Davie has also had periods in recovery when he has been doing well, taking part in stage productions and playing for Scotland in the Homeless World Cup.

But he relapsed last year, and in the last few months has been taking greater quantities of drugs than he had for years.

Now he is back in the early stages of recovery.

“I know where I can be, I know where I can get to… but time is running out,” Davie said.

“My goals are to have a good relationship with my daughter, get to see my grandkids, and spend time as a normal human being and as a father.”

Megan has been in and out of contact with her dad throughout her life.

When she told him she was using street valium, Davie blamed himself.

“I can see a lot of me in her, because of her age and, because that’s the way I used to be,” he said.

“I blame myself, because I wasn’t there to guide her and tell her to stay away from this and stay away from that.”

But Megan says she doesn’t blame her dad for her drug use, or for being absent during much of her life.

“I ended up on drugs because the men I chose, the friends I chose, the lifestyle I chose. I don’t for one minute think it’s my dad’s fault at all,” she said.

Megan says her dad had been “lost” and stuck in a lifestyle which meant he did not want her around.

“As an adult now my heart just breaks for him, because I’ve been there.”