God damn I could write so much on this shit now that I'm typing. The last post actually made me sad while typing because I have a very circuitous relationship with substance use but never quite got bad enough for rehab or deeply fucking up my life.
Addy and amphets also kill your appetite, and I was really into lifting and fitness from 20 until now, so I would even use to suppress my appetite and not eat for an entire day, just to try to get my body fat % down. Sort of like some of the psychos in the /fa forum. But it makes running and working out too easy when you're on it, so the offdays would be too hard. Thankfully I'm reformed off that shit and I never take it before working out, or if I do it's a really special circumstance like I have a really busy day and then have to fit in a 30-55 minute workout during a specific time slot in the evening. Good news is that I just run 30 miles a week now for leisure and to stay in shape and I'm doing ok.
But enough about myself. OP, I've always had time management and discipline problems myself. Addy has its merits, but its better to learn self control through other resources.
Resources I've used are a) talk therapy with a psychologist. Someone you respect or can form a relationship with. They don't fix you in one meeting. You go regularly weekly or every 2 weeks and work out your shit.
b) resources like books, podcasts, research articles, newsletter that are designed to increase your productivity. Other people suffer from these problems too, and the podcast versions are perhaps the most human where they talk about how they get through each and every hurdle, each and every temptation to fuck around on the internet or eat a piece of candy whatever. A great book is "Power of Habit". Bestseller list, blah blah. It's a quick read. Also random people post articles on how they focus throughout the day in op-eds on like Nytimes, Wall st journal etc.
I'm far from perfect myself. But I'm looking for long term sustainable happiness (as are a couple folks in this thread, which inspired me to vomit my 2...00 cents). Been looking for habits and patterns that I can take to my 30s, 40s, 50s whatever so that I can work on things that I love and make me feel fulfilled. And yes I've stared at a computer for 12.. 24 hours and somehow done nothing. Between Yea Forums, youtube, facebook, instagram, snapchat, whatever. They really do fuck us up.
Since it's /lit, I think Tim Wu has some cool books on the topic of platforms / apps trying to siphon our attention with distractions to accumulate tiny revenues that add up. One book is called "Attention Merchants" but he has others. As well as other researchers/ scholars who write on a similar subj