Nervous about next Remicade infusion(upping my dose to 7.5kg.)

I've been on Remicade for a year now(started in July 2009) and I had a blood test done and they said I'm not metabolizing the remicade right. Now they are upping my dose to 7.5kg. I'm nervous because I have reactions to remicade. I get chest pain(they say it is heart burn), I get a rash if I don't take my zyrtex, and I get joint pain. I'm scared that this will get worse. It is tolerable now but I'm just scared. I go on Wed(8-4) for my next infusion. I'm hoping this will work because I'm not ready for surgery. My symptoms are fine to me I go about 4-6 times a day and I've had no accidents(knock on wood). The remicade isn't healing my colon much and hopfully this will do it. She said she will let me stay on it alittle longer because my symptoms are fine but my colon isn't healing. She said I can't stay on it forever if it isn't healing my colon. She said she would worry about colon cancer. I asked her to give it another 6 months to a year. Just nervous and hope this infusion goes good and I don't get any bad side effects.

I get tylenol and hydrocrotisone before my infusion. Thanks I will let you know. God 15yrs old how horrible.