Is it possible for a dosage of medication to be to strong for you?

My doctor increased the dosage of my medication. I felt it was too strong right away, because I was feeling high. I didn’t stop the medication completely, I just went back down to my original dosage.

About a week later I started experiencing some strange symptoms. I was scared to get out of bed, lost my appetite, started using the bathroom A LOT more, my thoughts were all over the place. I couldn’t think straight, felt dizzy & overall just not like myself at all.

I have not had anything different besides the medication. Is it possible the increase of meds caused these symptoms? I go back to my doctor this Thursday & I’m hoping he will decrease the meds, if there is a chance they have caused these symptoms.