I sympathise. I rode down way out west a few weeks ago in search of an elusive babyshower. Some nasty roads. Although, I think you are right, the unfamiliarity makes it tougher. I worked in N. Kensington years ago and was fine once I had a few different routes I liked and which kept it from getting boring.
It isn't the best time of year to begin a new commute route either. Perhaps leave it till one beautiful morning weatherwise, and extend the commute, if you can, to leave out the bigger roads and perhaps squeeze in a bit of riverside to make it quieter and more enjoyable. That's what I do every now and then. My route is only 5 miles (I could make it three if I wanted to haul the SS up a gert big hill) but when there is a clear sky, beautiful sliver of moon in a sky which promises a lovely sunrise, I'll make it 12, and include some of my favourite bits of London.
What route are you using? I don't know where in Chiswick you are and I guess the A4 could be a nasty barrier to building a decent route, but I bet it can be done, even in the badlands of the West.
