He has 1 W, 1 S, and 1 Q result dropping from his total in the next few wks, Calabasas, Charlottesville, & Knoxville, respectively, for a total of 125 pts. He lost 1st rd at Tiburon last yr so that's an opportunity to gain pts. He also has the Champaign Challenger at the end of the yr, which he didn't play last year, another opportunity to add pts before the end of the yr. I'd say he's in good position to crack the top 100 by year's end, if he plays well.
Your last four words are the key, though. If he plays well. This time of season is usually his best, but for some reason he's been struggling, possibly if not likely due to the flu he had. He needs to pick it up, immediately. He has basically three events (Tiburon, Knoxville, Champaign) where he can gain points. He'll need to take advantage, and then try to defend as much as possible in the other two events.
I really hope the pressure of top 100 status isn't getting to Donald. Ever since he made it back in the top 100 is when he starting struggling. That will be the one thing going forward that could damage his chances.