What can I do to get rid of constant hallucinations?

See a psychiatrst. Hallucinations usually respond to meds (while delusions do not) work with your doc to find a drug and a dose that gets rid of them or at least dampens them.
Depends. If you are hallucinating it could be due to mental health issues and / or toxicity from chemicals or drugs. It would be important to see if there is a root cause first. And if so, to treat that cause of your hallucinations. If they are especially troubling, then i would go see your doctor right away as this could be a symptom of something more serious.