Apple Watch screen is black but still responsive

Hi, my Apple Watch has a problem. I charged it for a very long time because I forgot about it, but then when I was going to grab it it was on a black screen. The screen still works but it’s stuck on a black screen, and the assistive touch blue thing on the screen was showing with the black screen so I think the screen is still working. When I pinged it I got a response. I also heard the charge. What should I do? I’m worried.