Hi Jryan! You can't change the past, but you've taken control of your future and that's the best thing to focus on! :)
I quit at 43, after around 20 years of smoking, in the later years, about a pack a day or so. Sometimes less, sometimes more. I can't do anything about that. But from the moment I quit I started to make better choices about taking care of my health. I workout, I eat healthy, I keep my doctor's appointments. There isn't much more I can do beyond that, other than to enjoy life. Work hard, play hard, you know?
I think while we are smoking, the addiction works very hard to help us push away the realities of what we are truly doing to ourselves, in order to keep us hooked. When we quit, that's when we start to really see the reality of what cigarettes do. I've had several freakouts over that once I stopped smoking. Some days every freckle was cancer and and every sniffle meant the end. I think it's a normal part of your brain coming back to normal and rewiring itself after all the years of being controlled by the nicotine.
I remember not too long after I quit, I had an appointment to the dentist. No big deal, just a routine thing. I go regularly, so I had seen him just a few short months earlier. But all of a sudden, I was obsessed with thinking that I had oral cancer and any bump or mark was a tumour. I spent days and days before the appointment staring at my tongue in the mirror. Just freaking out. Finally the day of the appointment came. I was pretty sure I was about to be handed a death sentence. I never had a problem going to the dentist before. My dentist rocks! But this time, for the first time, I was scared to go to the dentist. The check up went just fine. All those days of worry for nothing.
I had a few months of that kind of thinking on and off and then it started to fade. I think it's normal. I always remind myself that the body also has an amazing capacity to repair itself, if we give it what it needs. Just take good care of you, and put your focus on living a good, happy life. And even if something comes up that you have to deal with, health-wise, down the road, you and your body will be much stronger and better able to deal with it as a non-smoker.