As the Good Book says:
The thing that hath been, it is that which shall be; and that which is done is that which shall be done: and
there is no new thing under the sun.
If you're happy that you are adding a new slant then I say Good for you, press on.
All the themes in my own poetry have been covered many times before by someone whether I know of it or not, but I'm happy that they have not been covered so well or in the same way.
There are very few topics in life really and no new ones.
I think if we worried too much about plagiarism, we'd never write anything.
