首先肯定一点，一定会有帮助的。
1.not only has Harvard given me an extraordinary honor ,but the weeks of fear and nausea I've experienced at the thought of giving this commencement adress have made me lose weight.
哈佛不只是给了我额外的荣耀，而且在毕业答辩/致辞前几周里所经历的恐惧与不适也帮我减了肥。
not only...but (also)是表示不仅...而且...的固定搭配，且not only引导的句子需要倒装，but后面跟的是一个主语从句。
2.I stopped pretending to myself that I was anything other than what I was,and began to direct all of my energy into finishing the only work that mattened to me.
我意识到自己是什么样的人，不再欺骗自己而胡思乱想，并且开始将精力投入到真正对我有意义的事情上。
stop doing sth停止做某事 work后面that引导的是一个定语从句。
3.The knowledge that you have emerged wiser and stronger from setback means that you are,ever after,secure in your ablility to survive.
你从失败和挫折中得到的知识使你变得更加睿智和坚强，这意味着你此后生存的能力更强。