I saw the following sentences in a picture (attached to the footnotes) and the way it's written exactly the same:
ありがとうございます が溢れて溢れて 悲しくて悲しくて 人にお花を買いたいと思う気持ち。
Since it's from a social media, I think the sentence was broken out and a part of it dropped to the following line. But I don't understand the reason why the sentence finished in the te-form and using the same verb two times.
Besides, as you can see, there is a line break between the two sentences, and the person used the te-form for the 悲しい adjective and I don't know whether is connected to the sentence or not, and I don't know if it's being used as an adverb or something else.
The person seemed to be breaking up with someone, because in another sentence that it's not in the picture, they used 別れ.