"Like Alex said - Definitely check your tire pressure. Low pressure will make your front squirrely on the road."
That's enough to cause that almost every time, every time you turn the wheel, and make the bike feel heavy on the road.
A little preventative maintenance, like checking tires pressures at least once every week or two, goes a long way, especially as the weather and temps change.
Hopefully that will solve your problem and it's usually the simple things that go first instead of looking for more exotic problems that don't exist.
