Sonnets and Twelfth Night

I think that it is really interesting that Shakespeare has written two types of literature where one piece focuses on a love steady and everlasting and the other piece focuses on a love that is weak and always changing. The steady love is shown in Shakespeare's sonnets; for example, both narrators in Sonnet 18 and 116 talk about never giving up on the love that they have for someone. Both narrators do not give up on the idea that the person they love will love them back. Twelfth Night on the other hand is totally different. There is this weird love triangle between most of the characters whose moods are constantly changing. For example, Orisno's has an undying love for Olivia one moment and the next he is not in love with her and then before you know it he is in love with her again. Another example would be Olivia. She makes it seem like she can never love anyone because she is depressed over her brother's passing; but then before you know it she is head over heals for Cesario who is really Viola. The love in the story is very unsteady and always changing. I have not read or seen this play before, but i do know this much, there are going to be some broken hearts by the end.