Feeling that someone is sitting on one

From about many years, I feel that somebody sits on me when I suddenly get awaken from my sleep. At that time, I use to be awake but suddenly my eyes get closed under pressure and my mouth gets closed. I try to shout but can't. I also feel somebody is walking in my room and from about a year I even hear some words which that person makes in my ear during that time which I don't understand. As a result of this, my heart has become very weak though I offer prayers five times a day and also recite ayat ul qursi and four quls (surah kafiroon, surah iklas. surah falaq. surah nas) but still undergo this. Same was happening with my father who passed away last year. Same also happens with my sister and mother but rarely. I even hear knocking sounds on door during this. Please tell me something about this.