Feeling someone's presence in the corner of my room when it's dark

15F. I've been feeling very unwell lately, being lazy, struggling with sin and being unable to stop no matter how much I want, feeling like God doesn't listen.

But I thought it was just a normal part of life and didn't think it could be caused by anything.

Until this happened.

It was around 2:00 when I finally decided i should go to sleep. So I brushed my teeth, changed into pjs and... Turned the lights off. And that's when my whole body started shaking. I just felt this chill run down my spine and I immediately hid under the covers. I was terrified. I felt something in the corner of my room, just in front of the door, watching me. And I also started hearing the sound of... Crickets??

But the worst thing is this is not the first time. I mean, the cricket sounds definitely are something new. That feeling of someone's presence has been there for a long time but never this intense and clear. And it's only there when it's dark. I always ignored this feeling but after this night I can say I'm 99% sure it is not just my imagination.

Is this some sort of demon? I started thinking and maybe this whatever it is is the cause of me feeling the way I feel? If it is a demon then what am I even supposed to do? I started rebuking it while hiding under covers but I don't think it worked?

Or maybe this is not a demon but an angel? But then why would I get so terrified of it's presence??

I'm writing this at 3:00, still hiding under the covers, I'll pray and try to fall asleep.