Is it normal that i was asleep but awake?

It is abselutely normal, it is calld Sleep Paralysis. This happens when your mind thinks that you are sleeping, but in real world you are awake. Your head is still dreaming sending a sort of image to your eyes causing you to hallucinate. As i said it 100 % normal and i have done it a few times myself. :)

Sleep paralysis most likely. Your mind still thinks your in REM sleep even though you are awake. You cannot move, it feels like doom, maybe a weight pressing down upon you. I've never experienced it, but just read up on it.

I can't tell for sure what you mean in your post, but check out, sleep paralysis. See if that relates to what you are going through.

I once had a dream that an alien from aliens was by my bed, my eyes were open an I was semi awake, I screamed and jumped out of bed, realised it was irrational and stopped and turned on the light. I felt stupid.

Sometimes I have them too where I'll be dreaming but I'm still awake. That's called a lucid dream. x

Lucid Dreaming and Sleep Paralysis?

Look both up and see which one you have.

Night terrors?

Those dreams are symptoms of a disease known as quitfuckinggeese syndrome. I was diagnosed at age 16.