My Strange Anxiety

hello,
a few nights ago i went to bed like normal but woke up at 1:00 am. I woke up with a sudden panic that someone who wanted to kill me was outside my bedroom door. Weirdly, when i went to sleep my door was properly closed and then when i woke at 1 am the door was slightly open. So, literally shaking i made my way across my bedroom and closed my door careful not to make a sound or look out my door. For about 20 minutes i was having a minor panic attack. I had never had anything like this before so that didn't help if anything that made me even more panicky. I shouted (what i thought was loudly) for my mum and she didn't reply. This made me terrified that my mum was dead and had been killed. So my plan B was to phone the home phone so it would ring out. And if my mum answered it she was alive and would come and help me calm down and if she didn't answer she would be dead and I would probably pluck up the courage and go into her bedroom. Luckily for me, she answered the phone and I basically told her to come into my bedroom. When she came in she said to me if i wanted to come and sleep in her bed tonight because my dad was away for the night. Sadly, for me my mum likes to sleep with her door open so if someone did come they could enter silently. So i have this theory that no-one would break in to kill after 4:00am. So at 4:00am I decided to go to sleep and as I had school i had to wake up at 6 am. :(
So: if you have anything like this please comment below and we can try to help each other out.
I hope if you have any anxiety that you find a way to deal as long as it is safe.
byee