It sound like an issue inside the gear box (transmission). First thing to get checked is the oil level in the gear box. It could be a simple case of being low on oil. Get it checked and maybe get an oil change. If the noise goes, you then need to find where the oil leaked from and get that fixed.
Here is an image of a dual-beam bulb. Note that it has 2 filaments as labelled:
You need to check if one of the filaments has fried. If the filament isokay for both high and low beam then you will need to replace your relay
Here is image of the fuse/relay block under the hood:
Check for the low beam as highlighted below:
Test the relay (https://www....