I had my amalgams replaced over 2 years ago. I am too sick now to do ALA/DMSA chelation. I did many rounds last year though.
If you can tolerate the chelation, then keep doing it. I am now taking 50 mg a day of iodine, and eating cilantro. I am also fighting candida with Now Candida Clear and olive leaf extract.

I would like to go back to ALA/DMSA.

Perhaps you should try taking 50 mg a day of iodine.

Is you temperature normal? Mine was below normal for a long time, but now it is getting closer to normal. I think the iodine is helping with this.

Perhaps your symptoms may be due to candida? Candida seems to flare up from chelation. Are you taking any antifungals?

http://www.flcv.com/cfsfm.html