Brown discharge after taking metronidazole

Hello, I have been dealing with this off and on for 3 years. Anymore with it i get this chunky toliet paper looking brown discharge

My dr keeps giving me metrogel for it but always returns few weeks -2months later. Does anyone else get this type.of discharge?i also get burning with it. Very uncomfortable. I’m seriously so sick of this. It has me so depressed. I just want relief. It’s a never ending issue.