home = dhachaidh
heart = cridhe
my = mo (with aspirate mutation)
So it should be
Dhachaidh mo chridhe
I don't know or speak Gaelic to any substantial degree, so I can't guarantee that this is accurate, but this is what I got out of my Teach Yourself Gaelic book. There may be other methods of getting "my".
By the way, there have been quite a few Gaelic questions in this site recently. Is there a quiz or something? I don't mind, I'm just interested to know where all the questions are coming from.