robinw, you're in my thoughts.
Sorry your dh is getting upset about your frequent journeys. I was doing a 2x90 minute drive to see my mum, mostly every other day in the last months. I used to leave my oldest son in the care of my dh, taking my young baby (I was breast feeding so he couldn't be away from me) in the car. Despite having a supportive dh, I too got comments about the time away, the dangers to myself and my baby of so much motorway driving (often dark, rainy conditions, extensive building building work on the motorway, tired driver etc,) and the effect my continual absences were having on my oldest son. I felt torn in so many directions. It really helped to talk this over with a few close mutual friends and my inlaws, just to gain an outsider's perspective. We all knew my dh cared for me and was trying in his own way to protect me.
No one could offer a solution, but I got another shoulder to cry on, and an idea of where my priorities lay from week to week.