Am I crazy or is there some form of SBMM?

The algorithm used for matchmaking does consider skill, but it's certainly not weighed as heavily as you may suspect. This is a team game and even if you do well, there's no guarantee that you will win the game. Playing a few games and losing all of them is statistically irrelevant. It could happen randomly. We tend to get frustrated when the game keeps putting us in losing matches, but we're quick to forget when the game keeps putting us in winning matches as well.

There may be other reasons why you end up in losing games more than average. If you leave the server every game to queue up again, chances are you'll be put in matches that are already in progress and where you aren't able to contribute as much to winning. Perhaps the only reason why the server has open slots, is because it was bleeding players on the losing team. That's why it generally pays off to stay in one particular server for more than one match.