latin help

Here is my modest attempt:

For "Protect my heart" we should have...

Protege cor meum.

For "Take care of my heart" we should have...

Cave cor meum.

Better linguists may correct these, and if so, wonderful. But, in case no one else provides anything for you, I do believe that these translations will convey what you want.

I agree with "Protege cor meum."

"Caveo" takes the dative, so I'd render that "Cave cordi meo."

For "My heart will go on": "Cor meum perget."