Well, I think demons do harass people, definitely. I suppose they sometimes disguise themselves as fallen angels, though actually I don't know much about fallen angels in terms of any activity from them today.
Here is something that I have found helpful when under demonic attack, in case it could benefit you, too. And I do pray for your peace and freedom.
This worked great for me when I was under attack, I believe, from some people who were into the "dark side." In the Bible we see that singing praises can be a form of spiritual warfare. David sang to Saul to give him relief from evil spirits. Paul and Silas were singing praises in prison when they were miraculously freed. Jehoshaphat saw various hostile armies coming against his nation of Israel, far too many to fight against. He sent out priests before them, carrying the Ark, and singing praise songs. The enemies all turned on one another and not one was left alive.
You do not have to, and probably should not, sing loudly. (Bad for the vocal cords if over done.) In fact if you are in bed, humming Christian praise songs can work well, too. Also, the attacks probably will recommence, at least at first, after awhile, maybe that same day, maybe another day. Use thi technique, like aspirin. That is, repeat when the discomfort returns.
There are many, many Scripture songs on YouTube. Here are some examples that you can sing along with. However, any praise based Christian songs can be greatly helpful. I think it really helps to sing TO the Father and His Son instead of about them. For example you can change "He's Got The Whole World In His Hands" to "You've got the whole world in your hands...." and so on.