Is it safe to perform the Valsalva maneuver while I have an ear infection? (plugging my nose and blowing to pop my ears). The discomfort is really bad, but I don't want to try it if it could make the pain worse or cause damage.

Valsalva maybe. If you have negative pressure in the middle ear space, gentle Valsalva might provide relief. If you have positive pressure, could make it worse. How do you know you have an ear infection? I'd discuss with someone who has examined your ears and seem your ear drums.