Claritin and medications

I took Claritin for many years it was my wonder drug. Early on I had some side effects such as heart palpations, very dry mouth, leg jumps and vivid dreams. I talked to my Dr. About the heart palpations but he never mentioned it could have been being caused by the Claritin. Anyway I took it when needed until my Dr. told me to take it every day and after about a year of that I started to get tremors, heart races and the shakes every time I took a dose. I quit Claritin all together and went 2 years taking nothing and now I am on Singular but it doesn't help me nearly as much as the Claritin did. I would like to try more medications but its hard for me because I am scared now of possible side effects.