Is this a form of insomnia?

I can go to sleep easily, i usually go to bed around 10:30 or 11, but i always (every night) wake up for no reason around 12:30 - 3:30 and then i can never fall back asleep and then on the days i do fall back asleep i have terrible nightmares about my deepest fear, water; i dont think that has anything to do with it but idk. Also, i have suffered from depression and self mutilation but i overcame that around January of this year but i am still very stressed and paranoid. Why does this happen? is my sleep pattern some sort of insomnia? Or something else?