Hi, Elena.
In reported speech, we often do something called 'backshifting'. This means that the Present Simple changes to the Past Simple, the Present Continuous changes to the Past Continuous, the Past Simple changes to the Past Perfect, etc.
For example:
Ken: "I like apples."
Peter: "Ken said he liked apples." It doesn't mean he liked them in the past, but no longer does, it's simply the way we often (but not always) backshift in reported speech.
In this case, it would be the speaker's choice to backshift or to say “Ken SAID he LIKES apples (because it’s still true)”, or even “Ken SAYS he lIKES apples.”
Another example:
If what Ken says is already in the past simple, we can backshift to the past perfect.
Ken: "I saw Sarah at the supermarket."
Peter: "Ken said he had seen Sarah at the supermarket." OR, without backshifting "Ken said he saw Sarah at the supermarket."
It's often simply the speaker's choice, but not always.
In your example: "He said he loved her", it’s simply a case of backshifting. If he no longer loved her you would report it as "He said he used to love her." (Or "He said he loved her once, but no longer does.").
If you can find some notes on the rules for reported speech, it will help you a lot.
Good luck with it!