The a fanfic author drops a new chapter my partner is at least as excited as I am when a new video game drops. There is nothing cringe about fanfiction, it is creative writing just as valid as writing a new piece from scratch, just with more context built right in. If you like fanfic then maybe writing it is a good idea for you
That said, when it comes to writing, reading is the key. Read lots and lots and lots, then write whatever takes your fancy, but never stop intaking new works. All writing is some sort of remixing and that is OK, you just want to have a lot to draw from and then write a lot of bad stuff to learn how to write well.
I’m 17 years without alcohol, 16 without “le drugs”, and 15 without smoking. I still have issues in my life and challenges to solve but wow, all of those would be harder and more numerous if I still behaved like I used to. I had a fairly short period of massive excess and had a few lucky moments of clarity which resulted in me quitting it all one after another. My partner and I have been together since just after I quit drinking and I am really glad they never had to see me being my worst self.
My biggest takeaway is it really does get easier with time. The hardest times were within a short time of quitting. The longer I sustained the more ingrained the change became and now I would be stubborn and resist any sort of backslide.