Attacks by demons when sleeping?

am 27 old female, i am often attacked by demons when sleeping. It comes and tries to kill me,block the air, i always try hardily to save myself by pushing him. Sometimes before their coming i see them i.e. my soul sees them but it does not help. And even they rape in dream. I feel real feelings i have orgasm sometimes. I need help. it happened to me many times for many years even in my home country. I thing someone made black magic on me. coz im very depressive, have unexplained fears, phobias, avoid people. when sleeping i can see them sometimes the demons, they have strange forms like liquid flying or black dust, tonight i was awakened by attack. they have entered into my body and made me weak for several minutes so that i was lying could not move but hardly tried to fight with it. in dreams i have pushed the black dust our of my mouth. that was dream but real feeling were there, so i guess my soul fighting with them while am sleeping. i am so tired of it. can someone give me advice plz. or advice some ppl who can help to fight with all this.