Hi everyone, I am on number 6 Kadcyla and coping pretty well. This came hard on the heels of starting Letrozole and radiotherapy so quite the triple whammy. Each cycle seems to be different. # 1 and 2 fine, 3 and 4 not as good and #5 I would hardly know I had had treatment. They have all been very manageable though with dry/light-sensitive eyes and some on/off fatigue being the main side effects. I was initially devastated to be on Kadcyla, especially as I only had 1.3mm of residual disease in the breast, but I am now pleased I am throwing everything at it. I just want rid of it forever and this is my best bet. 
For most Kadcyla is so much easier than TCHP.
Just an idea, but if you struggle you might ask to have the infusion over a hour or longer. Lots of people on another Kadcyla support forum say this helps. I ask to have mine over 60 minutes. I also wear compression socks and gloves to lessen the likelihood of neuropathy.
Wishing everyone all the best wherever you are on your Kadcyla journey. X