What you are experiencing is very real. Have you prayed to G-d about it?
I have also had experiences (but mostly dreams) like you are refering to since I was around 5yrs old.
There is spiritual warfare going on in this world all the time. Most people ignore it. You ARE being targeted by these beings, and they do not like you. You are a human, created in G-d's image. As a human you were origionally created by G-d to rule over this earth (in righteousness and peace), to cultivate the earth, to care for the animals on it, to excersise your creative gifts and talents to give HaShem (G-d) praise.
Satan (a fallen angelic being) was very jealous of the authority G-d gave mankind. He was bent on destroying this creation of G-d. (Read Genesis) He tempted the humans with wisdom, knowledge, & power. He planted doubt in their mind about the intentions and goodness of G-d. They believed the deception of Satan and disobeyed G-d. At that moment they gave up their spiritual authority & power on earth (which then gave Satan power & control.) G-d had to send the Messiah Yeshua (Jesus) to conquer Satan, save mankind, and IN MESSIAH we (human beings) again have power and spiritual authority over these demonic beings.
That is a VERY short summary!

If you aren't already, I'd suggest you read the Bible every day. The bible itself won't make the demons leave you alone- but if you fill your mind with the Word of G-d, you will be spiritually strengthened. You will gain insight into the spiritual battle that rages in this world. You will learn about the nature of G-d and the importance of Messiah.
The closer you move to G-d (the more He is calling YOU out of this world system) the more intense the demonic activity will probably become- so keep that in mind. Call out to the God of Abraham, Issac, and Jacob- the G-d of Israel- to save you from the grasp of the Enemy. If your heart calls out to Him, He will hear you, rescue you, and fill you with His Shalom (His peace and perfect order.) He will give you life instead of death, order instead of chaos, strength instead of fear.
I know the dreams are very scary. But if you have truly descided to leave the demons and get them out of your life for good- start by burning all of your occultic material. Any books, music, objects, jewlry, clothes, games- anything that has ANY connection to the occult- Burn it, dump it, get rid of it- ASAP.
There are actually "rules" in the spirit realm. If you have opened a door to the demonic beings, they will not leave unless you CLOSE that door.
A "door" can be calling up 'spirits of the dead' (which are really demons pretending to be dead humans). A "door" can be an insence holder you picked up at a New Age shop.
There can be generational curses- where one of your ancestors opened a "door" to demonic influence and that spirit was allowed to stay with your family down through the generations.
You CAN shut those spiritual "doors." You CAN break the generational curses. You cannot do it alone.
Do you know any strong believers in Messiah Yeshua (Jesus) that could give you support and protection during this time? Are there any "safe" people you can talk with about what is going on?
One more thing- you were targeted at an early age. There is a reason for that. Perhaps the Enemy knows that if you experience spiritual rebirth in Messiah (become "saved") you could do a lot of damage to his power on earth.
Yes, child, the Enemy of your life is watching you- but so is G-d, the creator of your life. You are precious to HaShem (G-d). He loves you. And He is able to pull you out of darkness into light.
Shalom~Nilahk