My my! Love or delusion… makes one seriously sick, too…
Lovesick (ness) – unable to think about anything except the person who you love, especially when your love is not reciprocated; missing the person one loves, being unable to behave normally.
Unrequited love – one-sided love or love that is not reciprocated.
Infatuation or being smitten – a strong, often foolish, feeling of love or interest in someone or something.
Limerence – a mental state of infatuation or obsession with another person, usually followed by delusions of or a desire for a romantic relationship with that person.
Obsessive love (obsessive love disorder) – a condition in which one person feels an overwhelming obsessive desire to possess and protect another person, sometimes with an inability to accept failure or rejection.
Easy English by Vesna 