Hi, the problems i keep having is when im standing up or if i am already standing up still, moving about

 i suddenly feel almost to week to stand, things sound quiet (dimmed), i can see mainly red and blue almost like eluminus paint splats that eventually stop me from seeing anything at all.

Then the shaking starts and theirs nothing i can do about it. My last "episode" caused me to head butt the radiator and split my face open. Luckily i was holding onto the door frame.Once my head made contact with the radiator i felt like i almost snapped out of the shaking but i couldn't see, my vision was still blurred and i was very confused, i couldn't concentrate on anything including a simple conversation.

Can anyone help me find out what this could be? Thank you