Did Persephone ever fall in love with hades?

No, Persephone hated being in the underworld with Hades. While in the underworld Persephone ate seven pomegranate seeds which caused her to have to stay with Hades for 7 months a year and her mother 5 months. During the 5 months the mother and daughter were together the land would be beautiful and bear fruit, but when the two were apart the land would be cold and harsh and bear no fruit.

Not true. Over time, Persephone did love Hades. Be it because of Stockholm Syndrome or real love, who knows. Winter was caused by Demeter's depression, being away from her daughter.