Very often I feel like a lot of my brain is devoted to emotion management much more than time management per se. I feel like I never achieve my targets whenever I set them, and I cannot micromanage my time because my productivity seems to be determined much more by emotional impulsivity to the point where it is having a detrimental effect on my ability to get work done. 

People have suggested things to me like meditation, journalling, and scheduling time to worry about specific things, but no matter what, that seems to be a finite resource in my brain that looks for something to worry about even if there are no specific triggers. This is something I've struggled with for at least a decade, and I've been on antidepressants and anti-anxiety medication in the past. I've found that ruminating thoughts seem to be sedated slightly with anti-depressants, although this hasn't completely rectified my ability to get things done with a clear mind. I would just like to be able to create a routine and follow it exactly so I can do exactly what I set out to do (but mostly study tasks) and at the moment there is a huge disparity between what I want to accomplish and what actually ends up getting done. Even things like the Pomodoro method don't work for me - even when I try focusing on one task for 20-25 minutes I find unwanted thoughts flooding in which defeats the purpose.

What have you folks tried that you have found helpful? Any effective strategies for keeping unwanted thoughts at bay whilst trying to work, be them psychological, organisational or even medicinal?