Could high blood pressure be causing my frequent urination and fatigue?

Not directly: The metabolic factors causing your high blood pressure could be contributing to frequent urination and fatigue. For example, an excess amount of sterols within the tissues of your cell and mitochodrial memebranes can reduce oxidative processes leading to a reliance on anaerobic metabolism. This metabolic imbalance can raise bp, reduce production of ATP and polyuria amongst other symptoms.