If you want to tell your spanish speaking lover that it's all over now you should use one of the following sentences:

-Ya no te quiero
-Ya no te amo
(both means 'I don't love you anymore)
or
-Ya no estoy enamorado/enamorada de ti
(I'm not in love with you anymore)

if you don't want to sound so harsh you can say:
-Quiero que sigamos como amigos
(meaning 'Let's just be friends)