I am on Biaxin for Laryngitis and an upper respiratory infection....

I am on Biaxin for Laryngitis and an upper respiratory infection. I went to the ER because I felt I couldn't clear my chest congestion and I was miserable. He prescribed me 500mg of Biaxin twice daily. I have just taken my 4th pill. Day 2 over. I have the stomach aches like everyone talks about. They feel like im starving, but I know im not because I just ate. Strange. The taste in my mouth is disgusting no doubt. It's a metallic taste, but not too bad. I keep drinking flavored waters and sucking on candies and that helps with the taste. I have had mild diarrhea today, twice. I actually have, previous to taking this medicine, a heart racing condition known as PSVT. I take medication for it to slow my heart down and lower my blood pressure. So far, thankfully, I have had no reaction in my heart to this medication but I am worried. I will keep this updated as it seems that most people started having more problems in days 3 and 4. hmmm. I have taken the Z-pack several times, (im always sick it seems like) and have never had any problems with it. I used to take amoxicillin, but it never seems to work on me. I think my body is now resistant do to taking it so often. I also take Zoloft for anxiety, so im pretty worried, ha ha, that I might have this severe depression or anxiety attack problem a lot of people seem to be having. Ill wait and see. I called the pharmacist tonight to tell him about my stomach problems and he said (Walgreens Pharmacy) that it was not an allergic reaction and would probably be fine, but to consult my doctor just in case. I will call tomorrow and update this if I end up having any other reactions or if he prescribes me something different.