Vinegar soaks might help with persistent foot fungi.
Usually, foot fungus is an itch between the toes. If you have it, and it hasn't disappeared after half a year of daily use of thuja salve, you might want to consider other options.
2-3 tablespoons 5 % vinegar
1 l warm water
Soak 2 times a day for 15 minutes. Repeat for at least a month.
The soak will help get rid of your toenail fungus, too -- if you file that nail down until it's very thin.
Or pour 5 % vinegar between the toes and let dry, twice a day. This shouldn't sting, except if things have progressed further.
Do remember to keep your feet dry. Take your B-vitamins, and back off the sugar intake for a while.
If the skin between your toes is white and cracked it's no longer simply fungal but also bacterial. The thuja will still help some, but it won't get completely rid of things. The vinegar soak will work nicely with bacteria, too.
In addition you might want to try one or the other antibacterial herb: try Echinacea internally and SJW (St. John's wort) oil (or salve) externally for a few weeks, and check if the color reverts back to a rosy red. Do add some calendula to the oil/salve, too, to help the skin heal, and don't ditch the thuja oil either. Don't use tinctures externally, they're not all that good an idea with skin troubles.
Next, the shoes: pour vinegar onto a bit of cotton wool and put that into all your shoes overnight. The fumes will kill off fungi. Repeat that, too, for a few weeks, so you won't reinfect your shoes / your shoes won't reinfect you.