I don't know why he hasn't returned your texts, but it sounds like he doesn't have any idea about the scholarship or looming deadline? If it were me, I would try a multipronged approach (text, call, receptionist) just focused on that. Something like unfortunately you haven't been able to reach him for several weeks, and now this thing is due, and is there any possible way he could complete it by Wed.?

I'm sure you have a lot of other feelings that will also need to be addressed eventually, but as you say you are doing good for now, I would just try to focus on this immediate task and save the rest for later. Good luck! I hope you get the scholarship.