"I love you with all my heart, but I don't know if you feel the same way about me."
Here's a breakdown:
* "Te quiero": Means "I love you" (a less formal and more affectionate expression than "te amo")
* "con todo mi corazón": Means "with all my heart"
* "pero no sé si tú sientes lo mismo por mí": Means "but I don't know if you feel the same way about me."
This phrase expresses a deep feeling of love but also uncertainty about whether the other person reciprocates those feelings.