I got clean for a few years between 2011-2015. Started using again because I was driving through that area of melbourne every day, started once a week, then every morning as a treat.
The minute you use again you do set yourself back to almost square one. once you're a few years out you will think oh one shot won't hurt. And no, it probably won't. but that one shot turns into one shot every day, then one each morning before work and one when you get home - just coz you can afford it - but then you lose your job, because even though you had enough cash for smack you didn't fix your car and it blew up.
I managed my first detox cold turkey after a hardcore trip at a doof on some NBOMe and had no withdrawals, felt all high on life and turned it all around. 3yrs clean wasn't bad. Now im the best part of 6 months clean but on methadone. tried for years with suboxone and even though i wasn't always in 'wd' i could never sleep properly, or eat properly - felt like shit all the time. preferred to spit my dose and sell my takeaways just to use a point a day instead.
45mg methadone has held me and made me able to live my life normally again - to eat, and sleep without sweating all the fucking time or waking up every 25 minutes.
Good Luck mate. The dragon is a hard beast to vanquish.