I was just wondering, how do people who were addcited to things prevent themselves from relapsing, and how do they deal with it mentally if they do?

Celebrate your small wins. They'll eventually lead you to your big ones. Every step you take towards your goal is progress, no matter how small!

I recently heard that cyclopentolate eye drop can cause addiction, and that is misused alot, but the doctor prescribed it for my grandfather for continuous use, is there any risk?

I don't really know what to say here it's just one question, How do I quit Self harm? I do it when sad , I do it when I'm mad. I can't control it, sometimes I even do it out of control I really need to know how to quit harming myself.

It's time you bury the hatchet. Tell yourself enough is enough, and cut smoking already. Yes, nicotine is relaxing and helps relieve stress. But at what cost? Being the most addictive substance on the planet??? You can learn to re-wire your brain to other habits to dealing with stress or other helathier habits in general. I tell you this because I did this. Good luck