How is seeing a doctor free?
I am having trouble sleeping as well by having (supernatural?) vivid dreams/nightmares. I am like asleep and then there is like some force that comes over my body and I can't escape from it and then normally a face appears (although is too blurry to make out as anyone recognizable normally). I had one just before where I was in bed asleep and it occurred and I was pushing on the wall to try to get away from it and it wasn't working, then I woke up/snapped out of it and my arms were beneath the side of my body.
Last night it was the same deal, force comes over body and face appears, I thought I was falling out of bed trying to get away from it, could have sworn I then hit my hand on the sharp corner of my bedside table and then soon after wake up/snap out of it and are still lying in bed.
Does the noise only happen at night? a few years ago I had trouble sleeping because I could always hear the sound of this high pitched ringing/squeeling sound in my ears, but only when I was in bed trying to sleep. I saw docters about it but there was nothing wrong with me, so I had trouble sleeping for months. Eventually my Dad discovered that it wasn't my ears at all, I owned a tamagotchi which I had jammed into the bottom of one of my junk draws when I out grew it. Eventually its battery began to leak and the acids corroded the circuts causing the speaker to make the squeeling sound that was disturbing my sleep.
Its not exactly the same I know but you should investigate other options before you worry about it being a tumour/medical condition, give your room a clean and keep an eye out for birds and their nests.
As for the nightmare, there are many people who have reocuring nightmares like that. When did these nightmares start? did anything happen to bring them on? often nightmares are caused by the stress of being affraid of having nightmares. Try to take control over your sleep, sleeping on your back can help you to avoid dreams and have you tried meditation? its a bit airy fairy but its confirmed to work. Otherwise talking about dreams can help stop them from happening again, so talk to your parents about it.