What to Do if the Dosage You Are on Is No Longer Working?

I know this may be a stupid question, but asking my doctor that I get stuck with is about as stupid as the question. I have been on Metoprolol Tartrate 50mgs 2x daily since 1995, and it seems that lately it is not keeping my BP where it should be. I do not know if the medication needs changing, the dosage changed to a higher dose, or what??????????? I know that I suffer from Severe Anxiety Disorder, Panic Disorder, and Depression. I have been under a MEGA amount of stress & constant feelings of anxiety/panic for the past month or so, and I am not sure if this could be what is keeping my BP elevated most of the time, or if something is going on with me. I did go to a heart doctor, but got to freaked out at the tests that he wanted to have done..just to prove to me that nothing was wrong.
My question is ...Is anyone else having issues with their BP being elevated and anxiety/panic/stress?