Well I for one do not need proof. I know what happened to me at the hands of grey aliens and others. Some experiences are very similar to yours.

They perform operations and do things to people that aren't nice. Some abductees have wonderful relationships with them and talk to them telepathically all the time. For all they have put me through, the relationship is strained at best.

I am not impressed by them and feel they have their own agenda which involves harming and using mankind for their own ends. I have seen no evidence to date which shows me any altruistic motives by any alien group.

You will need to make up your own mind on who they are to you.