It's very normal to have this happen with mercury. In fact, it is one of the tell tale signs is the roller coaster rides. Up and down. Which is why it makes it so very very hard.
Also you can have good or bad rounds, so you don't know how you are going to be always from one round to another. E.g. you can feel better ON round sometimes and other times you feel better OFF round. Then it can change again.
Unfortunately as you know, mercury is often responsible for the endocrine problems many of us have. So it is a many edged sword. What you need to deal with the mercury is being hampered by the mercury itself. This includes the organs of elimination too. This is why mercury is so difficult to treat.
