I don't even know why you ask if it is normal. It isn't. Please tell that to your psychiatrist he/she IS going to help you.

I don't know but when I was young I used to imagine super large things and then something really really small and that freaked me out to the point of crying. Like a super small thin hair and a huge...

As long you don't do it in front of others I don't see a problem. Don't worry.

That isn't even near to normal I recommend you see psychiatrist and I feel sorry for your family if that's true but I think you lost them. Nothing would be the same.