My professor blocked me again and now graduation is pushed to 6 years. I feel like my dua is unheard.

Assalamu alaikum. I never imagined I'd be writing this, but I'm at my wit's end. There's this professor who failed me on purpose last year, making my 4-year degree stretch to 5. I bore it with sabr, kept up my prayers, fasted, made dua day and night, thinking Allah would open a way. But now, the same professor has used their wasta to block my course registration completely. So my graduation is now delayed to 6 years. I'm beyond exhausted. The worst part is the doubt creeping in: why is Allah letting this happen? Did I not pray enough? Does He only answer those with power and connections? I see injustice winning and my duas seem to hit a wall. My iman is shaking, and I feel so empty. How do I fight this administrative oppression, and how do I keep my faith from crumbling when everything feels so unfair?