Anyone else still look substantially younger than their peers, despite decades of physical abuse?

I'm about to turn 40, and therefore trying to have better accountability when it comes to aging right. The past couple decades have been rough- with 80% of my 30s involving HEAVY (Liter + per day hard alc), dozens of pancreatitus hospital stays, couple years on the liver transplant list, as well as countless rehabs, detoxes, etc. In conjunction with these I haven't once exercised more than two hrs per week, had a highly processed diet, and smoked a half pack per day. I know I'm extremely unhealthy, in fact a mere mile long hike leaves me gasping for air...but...I finally feel like I'm ready to change. That said, I'm struggling to find the motivation when aesthetically, (BMI, skin, etc) I genuinely look 15 yrs younger than any of my peers. And I'm talking HEALTHY ass peers. Is the idea that my appearance won't be impacted just foolhardy? Will the years suddenly slam down hard? I realize I should make better choices simply for my liver/pancreas/energy- but it's hard to be disciplined when you've never been pressured due to appearance.