I have two turtles in one tank. Two days ago, one of these turtles got red flesh coming out of its tail and the other one was pulling it out.

I removed the hurt turtle from the aquarium and put it in a tub. It's perhaps its penis coming out of its tail, I saw here: https://www.youtube.com/watch?v=wcp4dF-mhz0

Since turtle's penis got injuried, it has stopped eating and penis is also not going back. Also I'm not entirely sure if it is a penis.

I am so worried, what should I do?

Here are few pics, showing how it looks: