I also cycle my commute. When I used to cycle to the old office this was 14 mile commute on a variety of surfaces. When I initially rode on the road I would gutter crawl; cars would pass real close.
Then I read a few tips on cycling safer and realised that my gutter crawling was actually very dangerous as cars will try to squeeze past to overtake. I don't know how confident you are but for me, riding a third into the lane at all times has improved my safety as cars will now only overtake if they have a ton of room and they'll always go way over into the other lane to do it. I will also take the full lane if I feel I need to. I essentially just needed to be more confident. YMMV
I've actually started moving further out and establishing my area on the road, and it has helped, but I'll often have to slow down and move in. Without typecasting it's often people in 4x4's (Range Rovers, X5s etc), I don't believe it's always down to the person driving it being, well, an asshat but due to the size of the vehicle changing your perspective.
Thankfully a lot of my commute is on cycle paths, but the quality level of road surfaces is some what variable.
Then I read a few tips on cycling safer and realised that my gutter crawling was actually very dangerous as cars will try to squeeze past to overtake. I don't know how confident you are but for me, riding a third into the lane at all times has improved my safety as cars will now only overtake if they have a ton of room and they'll always go way over into the other lane to do it. I will also take the full lane if I feel I need to. I essentially just needed to be more confident. YMMV