There is a voice in my head that says gay things when I am straight, would that be schizophreniak? It also says random things on my actions.

See psychiatrist now. If you actually hear an audible voice - like hearing the voice of someone when you are interacting with them - that comes from inside your head, this is more likely an auditory hallucination. This does not necessarily mean that you are schizophrenic, as many conditions can cause them - many that are easily treatable. For now do not respond to any of their commands or believe what is said.
Could be. See a psychiatrist to make the correct diagnosis there are medicines that r frequently effective in getting rid of voices.
Sexual obsessions. It may not be voices. Sexual obsessions are common symptoms of obsessive-compulsive disorder (ocd). The literal content of these obsessions superficially resembles other types of iterative sexual ideation, as seen in, ptsd, and normal sexual fantasy. However, their form, function, and effect on behavior vary greatly. A failure for a physician to distinguish these items can lead to wrong treatment.