You need look no further than at one of Catullus' most famous poems to see two extreme and opposing emotions expressed towards the same person.

I hate and I love. Why do I do it, perchance you might ask?
I don't know, but I feel it happening to me and I'm burning up.

This is one of his poems he wrote to Lesbia, and captures the dynamics of the relationships perfectly. On the one hand, he is madly in love with this woman. And, as you do when you are in love, you want to do anything to be with them and to gain their approval. Yet, on the other hand, Catullus hates what his love is doing to him and also hates his lover at the same time - perhaps because he is so desperate to be with her. This conflict - this paradox - is consuming him and eating him up with doubt and curiosity as to why he is like this. Such a short poem, yet eloquently describes how often so many of us feel in an unhealthy relationship.