Gaining Weight on Iodine :(

I started Lugol's (2%) a couple of weeks ago. Began with 3-5 vertical drops the first week and then raised it to 10 drops. I immediately began gaining weight (2 lbs overnight, 2 days in a row)!. Yesterday, I stopped the idodine and started supplementing with selenium, magnesium and vitamin c. Before this, I had only been using a multivitamin. I am also hypothyroid and on naturthroid, and cytomel though my tsh has always been good <1, but my free t3 and freet4 have been flagged low (now within range, but not "ideal"). I am very excited about Iodine and would like to start back up, but not when the scale is moving the wrong direction! I didn't take any today, so am giving myself a two day rest, and I also drank salt water today. I am going to get some b vitamins today as I heard this might help? Do you think it is safe to start back up tomorrow? Should I lower the dose? New to all of this! Thanks!