Hopefully it will get better (and the viz was really poor, but that's making excuses!)
No that's not making excuses. Visual navigation in poor visibility is really, really difficult. I remember not being able to find Sheffield - and I mean the town, not the airfield!!! In good visibility, when you can see for several miles, you fly your headings, the ground beneath you matches the chart, and it's easy and fun. Once the vis is down to 7 or 8km (it doesn't have to be really bad) it's much harder, and you really have to be on the ball to notice if your heading isn't working. That may be because the wind has changed or whatever, not because you're not flying accurately. And then, IMHO, is the time to use VOR and GPS and anything else you've got as a back-up.