11 months of chelation probably wasn't enough time, but only your body knows how much time it will take.
From my experience, you likely won't be able to cure yourself of yeast problems until you get rid of the metals. I would concentrate on getting rid of the metals if I were you. You will know when it's OK to stop. Your body will tell you. Among other things, you will just feel so much better and you likely won't react to a round of chelating anymore.
I've read about a few people whose yeast symptoms went away through chelation only. Actually, most of them didn't know they were yeast symptoms; they just described the symptoms going away.
If DMPS and DMSA are too expensive, there are people out there who use only ALA (in the Cutler Protocol). That's not so expensive.