YOU SAID:

i like this guy but he doesnt like me back

INTO JAPANESE

私はこの人のことが好きですが、彼は私を好きではありません

BACK INTO ENGLISH

I like this person but he doesn't like me

INTO JAPANESE

私はこの人が好きですが、彼は私のことを好きではありません

BACK INTO ENGLISH

I like this person but he doesn't like me