Not exactly the demographic you're looking for, but it may help.
I've been smoking dope for ~6 years now consistently (I'm 21 years old for reference) and really don't see it affecting my negatively.
I'm going to university to study Mechanical Engineering, have a 3.2 GPA, am Vice President of the most renown and respected engineering clubs on campus, have a girlfriend, worked two internships (only in my Sophomore year course work wise--- that's a decent accomplishment), and surf or climb ~3 times a week.
I keep myself pretty busy... but I still go most weeks indulging nearly every day. There are definitely exceptions where I'm just too busy and the thought never even crosses my mind, but most days I'll get high. In general though: If you're already a lazy, unorganized person, then pot will just exacerbate those qualities.
My general tips for being productive are as follows:
Find what strains work for you. There are a few sativa strains that make more productive than most other drugs could. Even coffee. After a long day, a quick hit of sativa will reboot my brain and make me motivated again to continue studying.
On this note, try to be very aware of how strains affect you personally. If I hit an OG or most heavy indicas, I notice it will heavily damper my studying efficiency. Be aware of how your highs are.
Be responsible about when you get high. I'll occasionally go to class high, or spend a whole day high. But these are on days I know that I don't have any big responsibilities to deal with.
If all else fails, save getting high as a treat. Take care of your shit, and only once you have alleviated yourself of all responsibility you get high (not after you take care of only one thing).
Occasionally, just take a week long break. For various reason, the main one being that you're mentally confirming that you're not reliant upon pot to get through life.
Pretty much anyone that knows me decently well knows I'm a pothead. My parents do (I still live with them; they don't mind as I have my shit together) and most of my classmates do as well. You don't have to let it define you. Anyone that thinks lesser of you because of it is probably not bright enough to be worth your time.