UC is really frustrating, and many folks spend a lot of time trying various treatments to get the symptoms under control.
You have a diagnosis, so I'll be the contrarian here and suggest a patient doesn't need a scope to start Remicaid. A number of guidelines state that scopes should not be used to "visualize" the disease: Treat the symptoms after diagnosis. Some docs like a scope when a patient has a major change in medication, but you've already jumped from 5-ASAs to Imuran without one, so that rationale is bunk.
You might push back on your GI or see if your GP can set it up, especially since this course of treatment is causing you so much anxiety. You might also suggest a sigmoidoscopy as a compromise.
Crohns is also treated with Remicaid.