Stage 1 Breast Cancer Her2+ finished my 6 rounds of chemo and 5 days of radiotherapy in October. Now 3 weekly Herceptin jabs and Alendronic Acid and Letrazole. Thought things would start to be on the up but are progressively getting worse. I dont feel tired, my joints are extremely weak, struggle to open jars and petrol cap on car, can hardly walk up amd down stairs. Anyone else had these side effects and know which one of the 3 it could be linked to.  I seem to get 1 day every 3 weeks where I can walk normal again.