Dear Linda -
NO! You cannot give up. I know it is a few days since your post and update, but hope you have a glimmer of improvement since then.
I STILL have shortness of breath from all my chemo - and it was NOT for lung mets. This is a normal side effect for those of us taking some strong chemo over and over for whatever mets we are fighting. Sorry that it is even worse with the lung mets.
I am off chemo now for 21 months and it has been a long, slow climb to get some stamina back. Big improvements walking uphill and stairs now, but NOT without a lot of effort to strengthen myself. There were times I WISHED for some oxygen!
Navelbine was a GREAT drug for me and knocked out my liver mets in combo with Taxol and Herceptin.
HANG IN THERE.
Smiles

and blessings.