Yosef told his brothers that he was not angry with them because it was H''s will for him to be brought to Mitzrayim. Another facet of the story is that Avraham was asked by H'' if he would rather see his descendants go through exile or to go to hell, to which he chose for them to be sent into exile. This was the beginning of Israel's exile to Egypt before receiving the Torah on Sinai.
You may not like where you are today, but you never know where you will be tomorrow. The day before he was sold into slavey, Yosef did not know that he had only one free day left for 22 years. But he chose to always be happy and look towards H'', just like Reb Noson OBM. Though he was attacked viciously his whole life for being Breslov, for the sake of the true tzaddik he stayed strong. Yosef had the aspect of the true tzaddik. Others attacked him but eventually realized that they had to do otherwise for the sake of all that's good and fair. The actions of others really do not matter much compared to a person's bold service of H''.
So don't be even the slightest bit sad in the process of what you are doing for Israel!