Some more info would be helpful, what kind of trouble are you having? Are the blinds re-stealing when you raise from the button, or are they calling and then putting pressure on you post-flop? What is the tournament structure?
Your range 3-handed should be nothing like your range at a full table, many more hands become playable and if the other two players are nits, I'm going to be raising 80%+ of hands from the button. It's vital to avoid becoming the short stack, because the other two are less likely to get into a big showdown with each other and allow you to ladder up.