Is this the end?

My dad was diagnosed last June (2018) with primary pancreatic and lung cancer. It spread to his abdominal and pelvic cavity’s found in a whipples procedure. They could not remove the growth. Dad has been so positive and had chemo since the procedure, but has recently taken a break due to tiredness and feeling poorly - my mum thinks due to his crohns. I’ve come home to see him (I live 150miles away) he seems a bit yellow, his voice hasn’t changed and he is simply physically exhausted. He’s not eating much and spends so much time in the bathroom. I have three young kids and a full time job and leaving to come is so hard but now I’m here I don’t want to leave. I feel so heartbroken. Is this the end? Do I put my babies first or my dad? I’ll never get this time back but my husband can’t easily take time off work. I feel so helpless. I need to be here for him, for mum and for me. I don’t want to go back. I’ve spent so long away (military) and I resent it all. :confused: I’m just completely at a loss as to what to do.