Zyrtec side effects

I have bad allergies year around but I am not able to take most medicines because the side effects are too bad. The last one I tried was Zyrtec which worked the best compared to anything else. However, after a few days I started getting really bad mood swings that lasted for a few days even after I stopped taking it. It was also very sedating and I could tell my reflexes were slower. I have tried Claritin, Allegra, and some over the counter meds but none seem to really get my allergies under control. Should I try shots and if so how effective are rapid shots?