A small part of me regrets quitting cigarettes?

I don't want this to sound like a post about how cool cigarettes are and the benefits to them, because there are none. They're extremely addictive, bad for your health and don't make you feel good either, just feel relieved from the withdrawal they themselves cause.

It's been 8 months since I quit but it's just very hard thinking about the time I used to smoke every day and how productive I would be after getting a major dopamine boost from making myself feel better. I would actually practice drawing, work on learning another language, feel the energy to talk to people and just enjoy life. Although I feel a lot healthier now, I don't feel any sort of mood that makes me want to do anything but sit around on my own and zone out.

Does anyone have any experience quitting an addiction and like, getting to a point where you TRULY don't feel like you need it anymore? It's been getting quite hard as of late.