Cant stop seeing and hearing things.!

So, this is very weird. Ever since I was a little kid I have been known to hear and see things such as just floating object, even faces sometimes, they are always dark (more shadowy) and hearing things but to nothing like screaming its always a whisper. ive had these problems as a kid and my parents knew. We never did anything because of the living arrangements, also when I turned fourteen my mother passed away. I did not feel depressed or anything because my mother and I was not very close. Now tho lately I have been hearing things alittle bit more and more every month or so. Words from "failure" to even "die" but not ever in sentances. sometimes in my moms voice or to my friends voices I hear at school even tho im trying to sleap in bed. I still only see shadowy faces from time to time. I also have weird moodswings of depression usually once a week for about a couple hours but then im back to normal.
I am sixteen and is seriously starting to cave in from all of this. I cant concentrate in school and wakes up frequently from noises. One last thing to note is that I sleapwalk apparantly. I dont know if that has anything to do with this just thought I would put that in there.
Please help!!!!