I’ll tell you how to fix it if you want.
I’ll tell you how to get rid of the fetish.
First, you have to jerk off every single day to women going to the toilet and you have to visit a public toilet and see one for yourself then employ a nice female friend to hold your hand while she goes to the toilet, then ask if you can beat the shit out of her arsehole and lick the toilet bowl. Ask if you can place your penis into the toilet water and jerk your penis off into the shitty toilet water leak around the rim of the bowl. Jerk off all over the toilet and go home. Repeat this process the next day repeat it every week until you are no longer curious about the toilet. Tell yourself you can have the toilet whenever you want. You can jerk off into a toilet bowl or watch someone piss on the toilet whenever you want it is not that special. There is really no reason to be curious about someone using the toilet, but if you really have to be that curious about it, by all means jerk off into a shit covered toilet. Use the dirty toilet water is penis lubricant every week for as long as it takes before you are no longer curious, and you know longer think it is forbidden.
When the forbidden fruit is no longer forbidden, but a dirty treat you can have at any moment with no moderation, and you know it’s disgusting, that’ll be the day you move onto a new fetish.