I have some ideas to share. I'd like to preface it by saying that you know yourself better than anyone and if what I say doesn't feel right please disregard.

I've studied core shamanism for around a decade and it's possible that the voices and sensing clowns and such could be you sensing things that really are there.

To get them to stop, if you'd like to try it you can ask that your loving, compassionate guardian angels to protect you from anything that isn't for your highest good. You can start talking to your guardian angels instead of listening to the unpleasant beings. Ask your guardians for healing often.

State the intention that you only allow helpful, compassionate, loving beings near you.

As far as the feeling of having powers it's possible that an unhelpful ghost or earth bound spirit is talking you into believing these things.

The good news is that these experiences could be trying to show you that you're a healer and you can do a lot of good in this world.

I'm happy to share resources and more ideas if you think it would be helpful. I'm sorry you're going through a difficult time.