Speech on Excellence in Education

I'm graduating from college next weekend. On May 5th I'm to speak at the honors dinner for students graduating with a 3.5 and over. I've been asked to speak on "Excellence in Education." I accepted the offer to speak nearly a month ago and have been desperately trying to write a speech in that time but for some reason I can't!!!! I've never had a problem writing speeches before but for some reason I can't get this one started. If I could get just a little help I would be so grateful. The past month has been so stressful and once this is out of my life I would be so happy!!!!! Please, please help me!

By the way the speech has to be about 3-4 minutes long!