YOU SAID:
i like the girl sitting next to me very much
INTO JAPANESE
私は隣に座っている女の子がとても好きです
BACK INTO ENGLISH
i love the girl sitting next to me
INTO JAPANESE
私は私の隣に座っている女の子が大好きです
BACK INTO ENGLISH
i love the girl sitting next to me
That didn't even make that much sense in English.