There are plenty of other fish in the sea

Meaning:

This saying  is used to say that there are many other people or possibilities, especially when one person or thing has been unsuitable or unsuccessful

Origin:

This proverb is often used as a consolation for losing a girlfriend or a boyfriend, and has been traced back to about 1573. First attested in the United states.  the proverb is found in varying forms: "Thereare plenty more fish in thesea"; "There are more fish in the sea than ever came out of it"; "The sea is full of other fish"; "There's more than one fish," etc.