Depression Hygiene

Hey girls! I’m working on recovering from a depressive state but during that time, I was unable to care for myself normally. That means I rarely showered, almost never brushed my teeth, and wasn’t eating enough. While showering and eating can be fixed in the blink of an eye, I’m concerned with how quickly my newly yellow teeth can be fixed. Can they return to my pearly whites with daily brushing or is this irreversible? Will I need fancy over the counter products? Anything’s helpful. I just want to go back to my old self.