First, is it possible to convince your doc to try a lower dose first, or to reduce the Metoprolol at lessen the effects of combining the meds?
If you find you absolutely cannot tolerate the Spironolactone, there are a few other medications, but I don't necessarily think they have less side effects. In addition, on most insurance, you must try and fail spiro first.

Good luck - I hope your body adjusts soon. This combination was difficult for my Mom when she was diagnosed with CHF.
Sue