Adueñas is from the verb adueñarse, meaning 'to take possession of' or 'to make yourself the owner of' something. It's built on the word dueño, which means 'owner'.
In this song, the singer asks, "¿Cómo te adueñas de todos mis sentidos?" (How do you take possession of all my senses?). He's using this powerful, dramatic word to describe how the person he loves has completely captivated him, becoming the 'owner' of his thoughts and feelings. It’s a very poetic way to express being totally mesmerized.
This song is a straight-up plea from someone who feels their relationship slipping away. Junior H lays out the feeling of distance when he sings, "Qué difícil es partir la cama en dos" (How hard it is to split the bed in two). He knows something is wrong, noticing "La nube que te estorba está enorme y no tarda en llover" (The cloud that bothers you is huge and it won't be long before it rains). He feels a huge disconnect and misses the physical affection, asking directly, "¿Qué tienen tus manos que no me tocan?" (What's wrong with your hands that they don't touch me?).
Despite the pain and distance, his core message is one of total devotion. He repeats the title line, "Nací para amarte" (I was born to love you), as the reason for everything. It's not just a feeling for him; it's his entire purpose. He's desperate to fix things and stop time from running out on their love, wishing that if something has to die, "que sea por fa' el reloj" (please let it be the clock). It's a passionate, almost obsessive declaration that he was made for this one person and can't imagine a life without them.