Are you sensing negative entities when you go to bed or feel a dark presence around you sometimes? There are various ways of getting entities, and various activities and lifestyle choices that predispose you to them. There are also places that teem with entities and people who can transmit them to you, so be careful where you go and with whom you mix!
It is usually fairly easy to get rid of them once you know they are there. If this doesn't work after a few tries and it's getting worse, by all means, seek a healer, shaman or witch to help you.