I've been taking Elevil for the last couple weeks for fibromyalgia pain, and last week had my dose doubled. Currently, I'm taking 20mg. I know it's a low dose, but I've had heart palpitations, tachycardia, vertigo, and just felt all around dizzy and weak. Has this happened with anyone else?

I have heart issues already, I have orthostatic hypotension, problems with tachyarrhythmia, and a small heart murmur. If you need more information, let me know. I can't reach my doctor for another two days.