TrendPulse|Her alcoholic father died and missed her wedding. She forgives him anyway.

Jillian Pizzolo remembers the bottles. The TrendPulselittle airplane-size bottles her late father, Steven Jencsik, hid to sneak alcohol. She remembers how inebriated he was, all the time. So much so that she started grieving him decades before he actually died last year at age 65.

"These little bits of grief have always been there even before he passed away, but it was just like the final gut punch once it finally happened," the 34-year-old Woodbridge, New Jersey, resident says ahead of her wedding day. "Because with addiction, you're constantly preparing yourself to sit there and say this potentially could be it. They could kill themselves doing this, and there's nothing you can do but sit there and watch somebody that you love do this to themselves."

More than 40 million Americans have dealt with a substance use disorder in the past year, a "treatable, chronic" disease, according to the Centers for Disease Control and Prevention. But just because it's treatable doesn't mean someone will get the help they need in time to prevent the worst. Nor does it take away the complicated grief that unfolds when that person dies.

"I don't want to sit there and paint him as some type of monster," Pizzolo adds, "because in those small moments that I did get him – and these are the moments that pain me thinking about that he won't be there at the wedding – because he was a good, genuine person at the end of the day, and he's missing his daughter's wedding."

'Just so out of control'

Pizzolo is one of seven kids – and the one who was closest to her father. Her parents split when she was around 7 or 8 years old; she always knew he was an alcoholic.

"As the years went on, he deteriorated more and more, and the relationships did as well," she says. She tried to maintain a connection but "had to keep my distance at points, because it was just so out of control," she says.

This isn't an uncommon phenomenon. "Grieving an alcoholic parent may have felt like an ambiguous loss far before they actually died," says Gina Moffa, licensed clinical social worker and author of "Moving On Doesn't Mean Letting Go." "When someone we knew succumbs to alcohol or substance use, we begin to lose pieces of them a little at a time. The person as we know them doesn't exist in the same way and we are forced to grieve someone who is deteriorating before us in different ways."

A complex developed in her mind – she wanted to heal him: "Being exposed to that type of thing, it definitely ages you and not understanding it fully, you want to not only change that person, but you want to make them better and do what you can, and I developed this whole mentality that if I did this, that maybe things would be different with us, maybe he would be different."

And it's just not true.

"Unfortunately, we cannot control someone's recovery or sobriety, as much as we wish we could, and the grief that comes with losing someone before they die can be devastating and traumatizing for someone," Moffa adds.

The complex grieving process

The alcoholism attached itself to his body, snuck into every orifice of who he was until just a shell was left, she says. "Eventually, it just dissipated to nothing." When she was 16 years old, he drank a case of beer and told her he started seeing things outside. He was later admitted to the hospital and had a heart attack.

"This is the type of stuff that I had to deal with, through my whole life with him," she says.

"Grieving someone who let them down is complex," says Jessica MacNair, licensed professional counselor. "There is no prescribed method to navigate this type of grief. It is highly personal and no one can expect anyone else to have a similar experience to one another."  

Plus: "While struggling with any mental health or substance use challenges can be painful and confusing while the person is alive, when they are no longer alive, it takes away the possibility that there can be any other outcome," Moffa says. "This is its own kind of grief."

'I just hope that he's at peace'

When Pizzolo got engaged last year, she called to tell her father. But "he was inebriated to the point that he could barely even comprehend what I was saying." Her wedding day finally arrived – more than a year after he died – and he managed to give her a present he couldn't in life.

"I joked with my mom beforehand with all the rain the weeks leading up to my wedding, that I asked my dad to do me one favor and make sure the fall foliage stayed and that it was beautiful outside," she says. "I like to think it was him, because it was a beautiful day all around."

Despite it all, she forgives him anyway: "I just hope that he's at peace with whatever he grappled with that he couldn't defeat in life."

If you'd like to share your thoughts on grief with USA TODAY for possible use in a future story, please take this survey here.