Side effects of Herceptin

Diagnosed with Her2+++, Oe+++ and Prog+++. Small Tumour, lumpectomy, 6xChemo, 6 weeks of rads. Started on Femera 3 months ago with bad se’s, particulary joint and muscle pain but also fatigue. Onc changed it to Rimadex last week so have only had 3 days of it but dont feel any better.
The question is how much these symptoms could be caused by Herceptin. I
ve just been on a site where many people attributed these se’s to Herceptin, especially in the last three months of having it. I am at then end of Herceptin treatment with 2 to go. I know we all find it difficult to work out whats caused what in those first 3 months with chemo and Herceptin simultaneiously. I didnt keep a detailed diary during treatment but kind of wish I had.
My Onc really neglected to tell me about many se’s. Always said “everyone responds so differently” blah. I always have to have a list of questions with me but even then the responses are minimal. I’ve learnt more in forums in the past 3 days than I’ve been told by the health professionals.

The fatigue could well be caused by the herceptin. I found I got really worn out towards the end of the year of herceptin. It started to be really noticeable about eight or nine months in, and then slowly went away after after I’d finished the herceptin.

I imagine the joint problems are down to femara/arimidex, but have no experience of these as I’m on tamoxifen

Thanks Roadrunner,
I will hope that, if nothing else, the tiredness retreats after I finish Herceptin. Wait and see on the joint and muscle pain I guess. I realise I just have to give it time and drop the “I should be…” More surrender…