For the most part, Ovid portrays love in a highly positive way, as something natural that arises on its own between two people. One of the typical signs of love in The Metamorphoses is when the two lovers can't stand to be apart from each other; thus Deucalion and Pyrrha, as well as Baucis and Philemon, each express the wish to die if their partner dies. Pyramus and Thisbe take this to an extreme extent when a misunderstanding makes them each commit suicide (their situation is kind of a precursor to Shakespeare's Romeo and Juliet). Even though Pyramus and Thisbe are otherwise portrayed as normal, loving people, their story hints at a darker side of love that Ovid also explores. This can be seen in the extreme possessiveness that makes Apollo kill his girlfriend Coronis after she cheats on him, or when Medea considers killing Jason because she is disturbed about falling in love with him.
Ovid portrays love as fragile, because it is always threatened by jealousy, possessiveness, and the human tendency to change one's mind.
Ovid portrays true love as giving people the strength to endure any adversity.