Is it normal to be scared of the dark every time you go to bed

It's perfectly normal.

The dark represents the unknown, and with the mindset of a human, you start imagining things that might be in there, despite even knowing those things don't exist because there is a possiblity within the unknown. When you're sleeping with someone, it calms you because it is something you recognize, a fellow human, and you feel a mutal connection through that, knowing that you aren't alone.

(Well, at least this is what I believe)

Haha, yeah it's normal. We're creatures of the light! we don't like not being able to see.

If possible you could try getting those light switches that turn off the lights automatically if you don't move for a while.

normal for me

To be honest I cannot sleep unless the TV is on. TV must be on and audible or else I just cannot sleep.

I'm an adult, and I'm scared of the dark, too.

I tell the monsters in my house not to come out until I'm already asleep, and usually I ask them to please stay out of my bedroom. I know monsters aren't real, but it helps my anxiety. It's particularly helpful if I have to go to the bathroom or something in the middle of the night, because then I can say "Monsters, please hide so you don't scare me", and talking distracts me from being scared. It sounds silly, but it really does help.