Your FT4 looks really good (even, perhaps, a tad high, but nothing to worry about), and you usually decrease levo by approximately 25 mcg when adding 5 mcg
Cytomel. So, the increase to 100, plus adding the
Cytomel might just have been too much, too fast. Now, you've been alternating for a while, got used to that, the Cytomel might be an altogether different experience.