That is true. Juliet says "O shut the door, and when thou hast done so, Come weep with me, past hope, past cure, past help!" This line is said to the Friar and means that she feels that there is no hope for her now that she is to be married to Paris. She is asking the friar to give them privacy and to weep and commiserate with her. To commiserate means to sympathize.
Every gerund has the same form - verb + -ing. So, having that in mind, the word <em>sleeping </em>is used as a gerund in this sentence, but it is also a subject of the sentence.
