my one of the sweet friends is a partitive construction. You wanted to mean one friend from your many sweet friends. But you have constructed the phrase incorrectly.

one of the sweet friends is correct. Here one is a determinative and it's a Fused Determinative Phrase in that construction.

A genitive case of a pronoun (i.e my) can't be used before a Fused Determinative Phrase.

Therefore my one of the sweet friends is incorrect grammatically.

my one of the sweet friends is a partitive construction. You wanted to mean one friend from your many sweet friends. But you have constructed the phrase incorrectly.

one of my sweet friends is correct. Here one is a determinative and it's a Fused Determinative Phrase in that construction.

A genitive case of a pronoun (i.e my) can't be used before a Fused Determinative Phrase.

Therefore my one of the sweet friends is incorrect grammatically.