"A penny of Pinellia ternata and a penny of callus can solve my three-point lovesickness, and one-fifth of my dreams are prosperous" is a relatively literary poem, which roughly means that a penny of Pinellia ternata (a Chinese herbal medicine) and a penny of callus (a Chinese herbal medicine) can alleviate my three-point lovesickness (this number may represent a small part).
This sentence may be expressing someone's yearning for another person, as well as memories and yearning for the same experience.