Trembling with nervousness

A while ago at work I was chosen by my leader to support from another line team. I was so excited because then I will be able to can get experience in another process. They teach taught me how to do the process and leave left me alone when they knew that I can do it by myself (all past tense). I was enjoying what I'm I was doing by that time that I didn't notice that our manager as well as the director was standing behind me watching what I'm doing. When I realized that they are behind me I suddenly trembled started trembling with nervousness that and I almost forgot the steps of the process. I just told to myself to relax, and that I'm doing the right thing.
I only felt at ease when they left me alone.


Need help to correct my grammar.:D