The funding cut will have a damaging effect on among other things American tech companies (Apple, Google and Microsoft). But most of all it hurts American reputation and influence. How can the U.S. be so out of touch with the rest of the world?
UNESCO is an organisation for education and aid. Will you act the same when it comes to the IAEA (the agency that the U.S. relies on to restrain nuclear weapon development by Iran and North Korea) or the WHO (that work with the Centers for Disease Control and Prevention in Atlanta to protect U.S. citizens from potential pandemics)? No, get a grips and take it like a man! You lost a voting, that's all! Happens to everyone sooner or later, and - surprise - in the U.N. and it's organizations votes do take place occasionally.
It's not the end of the world, your pride can survive this and more. At least it you don't embarrass yourself before the entire world by acting this childishly. As if the debacle in the U.N. security council wasn't enough already. For God's sake try to keep some dignity or you will become the laughing stock of the entire world.