Zyrtec and lyme

I was prescribed Zyrtec a few years ago for allergies. I also have MPV and need to take Atenolol, I will need to take Atenolol for the rest of my life. My cardiologist recommended I stop taking Zyrtec because it can give you an irregular heart beat. When I tried to stop it I got very bad withdrawal symptoms, chills,heart racing, insomnia, itchy skin. I thought I was going crazy, so I took one Zyrtec as soon as I took it 15 min later the symptoms stopped. The next night I decided to try and cut the pill in half and only take 5 mg, that was ok for 3 day's then the symptoms returned. I had to take the other half of the Zyrtec and then the symptoms went away.
I can not believe that I have to find a way to wean off Zyrtec. I am very annoyed that they do not list on the label that their could be withdrawal symptoms after taking Zyrtec for a while. I am not giving up I am going to continue and try to wean myself off the Zyrtec, hopefully I won't have a heart attack in my attempt to get off this drug. If anyone has a successful way to wean off Zyrtec please post it. Thanks and I hope this helped someone who was thinking of taking this drug. STAY AWAY FROM IT..