Is it normal that i paint upside down?

It's very common for artists to draw upside down! It's actually recommended by many professionals to draw things upside down in order to draw what you see rather than from what you know. It allows you to let go of the already established symbols you have in your head.

There's actually a physiological reason for it. You use your right brain, which is the creative lobe.

I'm an art college student and I had a teacher who always made us draw an upside down sketch before every drawing or painting, it's a great technique and it helped me a lot actually! Most people in my class hated that teacher because of this but I think you'd like her ahahaha

So

I do the same thing:) It helps, and it gives me a new perspective.

Sounds fucking cool

The last sentence pretty much answers your question.
Hm, but to me I do think it's normal. I for one draw sideways and sometimes draw in portrait a landscape picture and vice versa. Painting upside down is a bit unusual but doesn't really count as abnormal.

You should keep them upside down. It's your style and it sounds lovely:)