i am on my 3rd day of methylpred. last night i started feeling r...

i am on my 3rd day of methylpred. last night i started feeling really tired and weakness in my mucsles and today my heart rate is up and pounding. i am already on blood pressure meds. and it helps to slow down my heart rate and now this speeds it up. i am starting to cough my head off i feel like i am getting a bad chest cold. i hate this med it makes me flushed in my face and neck and keeps me awake. im afraid to stop taking it. but i don't want to feel like this. what happens if you quit taking it?