Thank you for your post, and sorry that you have found yourself on these forums.
I am sorry to hear that your husband was diagnosed with pancreatic cancer on his birthday - no time is a good time to get this diagnosis, but it seems particularly cruel for this to have happened on his birthday. I note that you are awaiting a liver biopsy - do you know what his current liver function blood tests are at the moment or not? And has he had a recent full blood count taken, which would tell you what his haemoglobin levels are?
Haemoglobin carries oxygen throughout the body - when it is low, this can cause extreme fatigue, shortness of breath, weakness and headaches also. It could be that this is causing his issues.
It could also be a side effect of medication - is he on any medication, in particular, opioid pain relief?
Is he jaundiced, as this can also cause fatigue?
Is he eating well or not? Energy can be derived from our food, so if the intake is low, then the energy levels can also drop.
The cancer can also cause fatigue in itself, but as you can see, there may be several causes.
Please do contact us - details below, so that we can go through these further with you.
Pancreatic Cancer Specialist Nurse
Pancreatic Cancer UK
support line: 0808 801 0707