New to multis?

I've just started playing multis online, I'm usually a sit and go and cash game player. I'm finding I'm having trouble buidling any kind of chipstack and when I am able to keep up with the average stack, a bad beat takes me out ALWAYS. I'm good enough to make sure I get my money in there with the edge almost all the time and I def don't take unneccesary risks; but I'm still coming up short. To win one of these things do you just have to pretty much get lucky at a key time or am I missing something. I feel like although I make all the right decisions all the time I still am losing; and I know that Sklansky says everyone gets the same amount of bad and good cards in the long run but Holy Hell lol. Any suggestions?