What happens if I separate my brain's left and right hemispheres?

If they can not communicate with eachother you'll obviously lose grip on reality and time.

Like the left side is the creative side, and the right the serious one..... they have to Communicate.

You'll keep in contact with both btw.

This has actually been performed several times for patients with epilepsy as a last resort to stop psychic storms.  Normal vision is split into left and right fields (both eyes) by a vertical line.  and the left or right brain see only their half of the field.  After split brain experiments (voluntary by patients), both half brains can speak but can only see half a field of vision.  Use a search engine for ... split brain ... to find many interesting articles.

Extreme cases of epilepsy may actually require that the corpus callosum be surgically severed (the neural bridge that connects left and right hemispheres).

If an object was flashed infront of the left eye, it could not be described verbally because the right hemisphere does not have well-developed language skills.  However, the right side of the brain could still recognize the object if it was asked to feel (with the left hand) and select the object it had seen.

Similarly, the left hemisphere has trouble recognizing patterns viewed out of the right eye (because the left hemisphere is oriented for language).

Normal brains work as a whole, so "sides" don't really play a large importance.  But when the corpus collusom is cut the two sides of the brain work independently of each other.  If you asked the same question to a split-brain person, they may answer differently for both sides of the brain (assuming that the person had trained themselves to be able to answer a question with methods adequate to both sides of the brain).

So the "I" still would exist in both sides, and could be different... also it would be expressed in radically different ways depending on the hemisphere you were communicating with.

This is precisely what's done in a surgical procedure called a corpus callosotomy which is a treatment for medically refractory seizure disorders.