What's going on with Justin?! Yesterday was a frantic day for him and Hailey as they went around town from doctors' appointments to home visits and even to the hospital!

The day started with a visit to the same medical center in Beverly Hills that Justin's visited almost every day for the past week. The couple went together, leading us to speculate it could be something to do with Hailey and fertility? Pregnancy? Who knows!

Then Mr. and Mrs. Bieber went to visit a home in Encino that's on the market for $13 million! The couple's been house hunting as of late -- but more on that later (stay tuned for our EXCLUSIVE story about the homes Hailey and Justin are considering buying and why).

After that, the pair had their chauffeured SUV pull into the parking lot at Children's Hospital LA in Encino. They stayed in the car, parked in the lot for about five minutes, then turned around and left.

Then -- straight to a "brain clinic" in Orange County called Amen Clinic. Here's how the clinic is described on their web site:
    "At Amen Clinics, it all starts with you. We look at your biological, psychological, social and spiritual influences to get a complete picture of who you are as a person. With life coaching, nutritional guidance and personalized therapy, we provide the tools you need to feel confident, complete and hopeful for the future. We are dedicated to helping you find the answer to you."

They offer everything from simple therapy, to ketamine injections, to microcurrent therapy. What's Justin doing there?!

We know he's been suffering from something -- is it depression, anxiety and panic attacks, nervousness -- something that's caused him to have trembling attacks and be hyper-emotional. Is this all related to his ex Selena Gomez? Is it the pressure of a young marriage? Fame?

So many questions ... but watch Justin as he makes his way into the elevator at the clinic (above video). Why's he walking so strangely? Is he injured? Or is he having a breakdown? We hope neither!