I increased my dose of Concerta and felt very bad. What should I do now?

I have been diagnosed with Attention Deficit Disorder (ADD) for over a year now and we had found the perfect dosage with Concerta 18 mg combined with 10 mg of Ritalin in the afternoon as needed. This summer, I noticed a decrease in my concentration level and discussed it with my doctor who authorized an increase in my Concerta dosage to 27 mg in order to eliminate the Ritalin 10 mg. However, the first day I took the 27 mg Concerta tablet, I experienced many side effects that I had never experienced before such as heart palpitations, a constant feeling of anxiety and a loss of appetite. However, the focus was there. I had taken the tablet very early in the morning (around 6am) and I felt these effects quite intensely from around 10am until 3pm-4pm. Since then, I did not dare to take another dose because I did not like the effect it had on me. I was wondering if it's normal to have so many side effects and if that would mean that the "dose" is too strong for my system? Thank you very much!