Yeah, having no expectations is the ultimate goal in order to get rid of unnecessary sadness. That said, it is probably impossible not to have any kind of expectations (for example, how could we ever take a death of our relatives for granted? or becoming homeless?), so we just have to try our best. I think I improved during my journey around Central/South America as I understood that every time I tried to picture what the next place would look like, I was wrong.
About fighting the sadness. Well, knowing the fact what I want and need to do (at least I think I know) with my life, helps me a lot to overcome any kind of sadness as long as I follow my path. I guess I would become depressed if I stopped doing what I want to do with my life and started chasing someone else's dreams. You know what I mean? So I guess the best way to fight sadness is just to keep on going and adapting to the situation. The world doesn't care about our dreams and wishes; it only cares about the reality. So we have to adapt our wishes to the reality to avoid getting down.
Oh yes, I followed you as well!