Metoprolol stomach upset?

I started taking 12.5mg of metoprolol a week ago. By day 3 i noticed i was nauseous, having diarrhea, and lack of appetite. I have other GI issues so its been hard to tell if its that or a side effect of the beta blocker. Are nausea, diarrhea, and lack of appetite common side effects? If so, will they get better as time goes on taking the med?

I just got increased to 25mg starting today (it wasn't lowering my heart rate at all on the 12.5mg). I have inappropriate sinus tachycardia and its made my feel like garbage. But yeah...not sure if the stomach upset is common or what