Suggest Treatment For Fast Heart Rate While Lying Down

I had a whiplash injury 18 months ago and unable to work. For first three months I had to sleep upright because dropping my head made my heart rate very high. Since then I have multiple symptoms including heart racing with exertion and heat. Low blood pressure, shortness of breath, digestive problems, pressure in back of my head, nausea and dizziness. I also wake up with fast heart when lying down, when I sit up it slows.