schell, personally, I don’t use TAF for the kind of focus you need. If that’s your objective I would start out with a low dose and work my way up from there. This is one of those molecules that invoke different responses from person to person, it’s not only subjective but dose dependent.
Check out this thread. It’s info, on the whole, about TAF, compiled by the Human Goole 
… and not solely dedicated to “erotic properties” as the title suggests. 
For focus/drive you can try P79, alone, or in combination with TAF and see if it gives you what you’re looking for. Careful, once again, start low. There are reports that this one can make you aggressive and argumentative at too high a dose. I use it for drive, but not in the same context.
Hope that helps. 
Bella