I don't think you can ever get rid of a fetish. It is not even fair to try. As long as it is within proper boundaries, respect, etc., you should not torture yourself by trying to get rid of it.
I say this because I have a foot fetish myself. It overtook me at a young age. I don't think there was anything traumatic that triggered it. Frankly, I follow a neurological theory I read once that there are some permanent 'crosstalks' across brain networks and some things can get associated with others. Colors can bring up a number, feet can bring arousal, as an example.
Personally, I masturbate to women's feet all the time and it does not bother me at all. It relaxes me after all. The only issue is finding a partner that enjoys it. My wife doesn't and it even caused our opening of the marriage. I have not acted upon it because it is very very difficult to find a woman who enjoys her feet adored. Only once I had a girlfriend that loved it. A truly unique woman as she liked her feet and even would lick them herself. Dietcherry on this thread seems to be one of them, kudos to her!