By constantly repeating ‘I have thought so much’ Bhatt is emphasizing that she thinks the girl constantly and the memory of her seems like a precious treasure to the poet.
The most effective way in which Bhatt conveys the importance of the memory to her and how unwilling she is of letting it go, is through the phrases ‘unwilling to user for a metaphor for a nice image’ and ‘most of all unwilling to forget her or to explain to anyone the greatness…’
By stating that she wont turn the girl into a metaphor for something nice (perhaps something you’ve seen in a tourist photo), Bhatt is emphasizing that the girls greatness is so grand that turning her into anything else would not do her justice. She wants to remember the girl exactly like she was, not comparing her to something else.
In the latter quote, Bhatt literally says she does not want to forget the girl, another way of emphasizing her unwillingness and she says she will not explain to anyone how amazing the girl is. She may do this, perhaps, because no one else would understand the strength and greatness the girl portrays.
The poet then does not write to entertain, but to put down the memory of something important to her that she can not speak aloud, for if she speaks of the memory, out it into words, her mind may put the image to rest. When she wants it to stay vivid and strong (just like the girl).