Why do diet pills and sugar blockers cause me heart palpitations and anxiety. these were prescribed by a doc. should i continue?

Stop: These pills are giving you side effects. Need to talk to the doctor who prescribed them. Till then and after a work-up you can decide how to proceed.

Diet pills: You did not say what diet pills you are taking but many are similar to amphetamines, which can cause increased heart rate & blood pressure. Some people are very sensitive to amphetamines & need a smaller dose. Also, they are contraindicated in people w/ cardiac problems or who have a family history cardiac problems. Perhaps another doc can address the "sugar blockers" part of your question.