Here's the English translation of the text you provided:
"How tiring it is not to be with you. Only when you, my teacher, sit beside me, can I rest and is my soul calm. Then I kiss your hands and lay my head on your blessed shoulders. Oh, how easy things are then. Then I wish for only one thing – to fall asleep, to forever fall asleep on your shoulders, in your embrace. Oh, what happiness I feel when you are close to me. Where are you? Where have you flown off to? It is so difficult for me, with such longing in my heart… But, my beloved mentor, say nothing to Anya [Anya Vyrubova, Alexandra's friend and confidante] about my suffering when you are not with me. Anya is good, she is kind, she loves me, but tell her nothing of my sorrow. Will you be with me soon? Come quickly. I am waiting for you and feel miserable without you. Give me your holy blessing, and I kiss your blessed hands. I love you forever. Mama.”