loosing weight

I still need to loose weight and I seem to be going the wrong way!!!!!! We are going to Hawaii in two weeks and I am going to look like a beached whale!!Does anyone have any good advice?? I eat a Slimfast and egg for breakfast and I eat a V8juice and kellogg bar for lunch and for dinner I have a bowl of Kellogg bran cereal. I try real hard to watch my sweets. I have a hard time excercising because my joints in my hands and feet hurt so bad!!! I can't afford a weight loss program!