What is your heart rate? You can take low doses of metoprolol to help slow the HR. I was very vagal and was able to use small amounts of metoprolol (12 mg - 25 mg) during the day to help when the PACs were overly annoying. Of course, we are all different in responses to drugs.
Remember that the PACs... reflect the time between beats... or a shortening of the refractory period and typically, PACs indicate not enough magnesium primarily and then you need optimal potassium to slow the time between beats... once you are optimized in magnesium. That can take some time.
Don't over-do the water intake... about 8 eight-ounce glasses should be more than adequate unless you are perspiring significantly. A bit of sodium is okay as the body needs some; just not the typical high amounts in most packaged, prepared foods.
Consider using a low-sodium V8 type veggie drink as another source of potassium. Organic, if you can find it,
Also avoid Gatorade as it has lots of sugar from bad sources.... and sugar depletes magnesium quickly. Also, it contains way too much sodium and only a minor amount of potassium (65 mg versus 250 sodium)...plus colorings and other unhealthy stuff.
Jackie