If you haven't already done so, you could try this:

Switch the two high beam bulbs, and see the bulb is still dim in the other socket. If so, it's the bulb; if not, it's obviously something in the electrical circuit.

If the bulb checks out ok after the switch, you could check carefully for corrosion on the contacts of the dim socket. Corrosion could affect the current flow, reducing the brightness of any bulb placed into that socket.

The highbeam indicator may not be lighting because of the reduced current flow -- it might appear to the electrical system as a burnt-out bulb -- it depends on the wiring in a 98, with which I'm not intimately acquainted.

Good luck, electrical problems are the worst!