"Portia, dear, would you mind going with me that day, when I confront those old gentlemen?"

She shrank a little, but said:

"N-o; if my being with you would help hearten you. But—would it be quite proper, do you think?"

"No, I don't know that it would—in fact, I'm afraid it wouldn't; but, you see, there's so much dependent upon it that—"

"Then I'll go anyway, proper or improper," she said, with a beautiful and generous enthusiasm. "Oh, I shall be so happy to think I'm helping!"

1）if my being with you would help...请教老师being是什么用法，该如何理解？

2)  so much dependent upon it...dependent这里是名词，但查词典，发现没有符合上文中的含义，这是怎么回事呢？