I was reading about your experiences and I hope you do not mind some more friendly advice.
I've seen some wonderful suggestions here already, but if all else fails, sounds to me like you might need an energy worker who is also a sensitive. When an entity has enough strength to manipulate the energy surrounding itself, and you, then you need someone who can basically do the same while being able to communicate as well.
I know for fact that using these means can greatly help with spirit transference. After this is complete, it would be a good idea to do a traditional house blessing and self clearing to help protect yourself from any re-attachment of others while you are still recovering spiritually from this one. I am an energy healer and sensitive, and I have conducted spirit transference many times using this process, so I speak from experience.
I'm not sure what resources you have around you, but you may need to look into finding an intuitive energy worker, reiki practitioner, etc., in order to come in and assess your situation. If you truly wish the attachment to be broken, it can be done as long as you find the right approach and are committed to the process. Don't lose hope.
Hope this helps you in some way.