Amy's father Mitch said at her funeral the late star was "happier than she had been for years" at the time of her death and claimed she had beaten drug addiction a few years ago, while friends believe her recent decision to stop drinking alcohol was down to wanting a settled future with Reg.
The source added: "Amy spent a week in rehab in June and told loved ones afterwards she was determined to quit drinking.
"She was planning her future with Reg and that was playing a huge part in her thinking.
"Amy was adamant about sorting herself out. Reg's proposal made her even more determined.
"She didn't want to carry on the way she was."
Meanwhile, Mitch has met with British Members of Parliament to talk about his plans to set up the Amy Winehouse Foundation, a charitable organisation to fund a rehab unit to help young people who cannot afford private care, and called for more public funding into similar schemes.
He said: "This isn't only important to me, this is important to our whole country. There's hundreds of thousands of young people in situations today that could be avoided.
"These are our future policemen, doctors and lawyers and solicitors, that we could help."
Labour politician Keith Vaz said he supported Mitch's campaign, saying: "It seems that the level of support is not there, with the closure of the teenage rehabilitation centre last year and what appears to be an inconsistency of funding."
- BANG! Showbiz
