YOU SAID:

I was walking down the [noun] when a [noun] came up to me and [verb] on me.

INTO JAPANESE

[名詞]が私のところに来て、私の上に[動詞]が来たとき、私は[名詞]を歩いていた。

BACK INTO ENGLISH

[Noun] came to me and [verb] came over me, I was walking on [noun].

INTO JAPANESE

[名詞]が私に来て、動詞が私の上に来た、私は[名詞]を歩いていた。

BACK INTO ENGLISH

[Noun] came to me, a verb came over me, I was walking on [noun].

INTO JAPANESE

[名詞]が私に来た、動詞が私に来た、私は[noun]を歩いていた。

BACK INTO ENGLISH

[Noun] came to me, a verb came to me, I was walking in [noun].

INTO JAPANESE

[名詞]が私に来た、動詞が私に来た、私は[名詞]で歩いていた。

BACK INTO ENGLISH

[Noun] came to me, a verb came to me, I was walking in [noun].