Don't mean to solicit but I think it applies here. I am a Masters student in Marriage and Family Therapy that plans to apply to dental school after my program. Anyways, about a year ago I started a coaching business that helps people achieve their goals, and particularly larger ones that loom over their heads like academic theses and standardized exams. You can learn more about the unique style of the program at countabilitycoaching.com, and feel free to message me on here if you wanna talk about it.
Long story short, I sit with you to map out your daily schedule, and then give you a morning briefing reminding you of your plan for the day, and also check in with you to check if you're on track (and help you readjust your schedule if not!). Honestly, having someone to be accountable to has been very helpful for every single one of my clients, and they've all found it very valuable. If you know this is a service you need, then I'd highly recommend giving it a shot.
Okay, now that I've marketed that lol, here's another option. Build regular habits. Anything, honestly, but be consistent. Strengthening your willpower in one area carries over and strengthens it in others as well. Here is a summary of The Power of Habit by Charles Duhigg (www.deconstructingexcellence.com/the-power-of-habit-summary/). Give it a look and implement consistent routines to cues you have everyday. Once you established a couple, try to do the same with daily study habits for the DAT.