What you are describing is not poltergeist activity. It is most definitley trying to make it's presence known to you. I doubt that it is evil or demonic. It sounds much more like a spirit that either came with the house or a family or friend that wants to relay a message to you. I guess I/we would need to know more about the house to give you a more accurate opinion. Like how long have you lived there? And has this been going on the whole time? Did you recently lose a friend or family member that you were very close to? Things like that. It almost sounds like a father/mother figure by the way he/she sits on the end of the bed watching over you.
You may very well have one or many spirits on the property from what you are describing. And it sounds as if one or more of them are protecting you. If that's true nothing is going to try and kill you these protective spirits will block it. You say that nothing works in getting rid of these spirits which may well happen since spirits live by the same laws as souls with physical bodies. God gave them free will also, including dark forces. I believe that you are safe in this house and that you do have protective spirits at your side so your prayers may in fact have worked to contain these not so nice entities. I think your doing pretty well with dealing with this. If other things continue to happen please feel free to keep writing.