For years I had similar experiences but after learning some traffic practices the incidence of potential serious problems is way, way down. You may find this interesting and instructive.

http://bicyclesafe.com/

For what it may be worth, even though I use my lane position to give other road users an indication of whether or not the lane is wide enough for safe sharing and strongly advocate the practice, if my speed were low enough I could well have been found in the same unhappy position you were.