Not Working

I have been taking this type of anti histamine since it was first available, after my last one stopped working. I started off with the normal one tablet a day then I progressed onto two only it seems that this one has now stopped working my lungs are starting to feel sore, I wake each morning feeling congested and I am sneezing even on a low pollen day and i have earache. it will take ages to get an appointment with my doctor :(