the low beam on the passanger side won't come on?

Broken wires don't typically work once in a while when you "mess" with it, but what you're describing sounds like how a bad connection in the socket acts. You know the common ground wire is okay because the high beam works. I would grab a test light and check for voltage at the socket. If you find it there right on the terminal, it's not making good contact with the terminal on the bulb. Look for the terminal in the socket to be corroded or spread open. Often you can use a pick to bend it tighter.

If you don't have voltage at the socket, you'll have to follow the wire back to where it's spliced to the wire for the left side. That splice is a good place to find corrosion.