I went to an Episcopalian priest several years ago and it didn't help. Also looked into deliverance and went to a psychologist who was an evangelican Christian. Like you, I had felt possessed. Eventually I was diagnosed with DDNOS, a condition similar to DID but without the loses of cognitive memory.

Therapy has been long and hard. Whatever your situation, I wish you the best of luck and success in dealing with it, in whatever way works for you.