Relationship with someone on a fiancé visa broken down

Hi,
I am a settled non EU , i applied for a fiance visa for my fiance with the intention to marry, but unfortunately our relationship has broken down and we are unlikely to marry.

The fiance has returned to her home country having stayed in UK for about one month out of the 6 months on the visa. Her visa is still valid with weeks remaining on the original 6 months validity period.

My question is what can i do? i am required to inform the home office of the breakdown as i fear this may affect my future applications

Inform UKBA as required, and stop worrying.

Just because your relationship broke down doesn't mean that it will affect any partner / spouse applications in the future (.... unless you make it a habit! ).

Thanks so much for your reply.
I will write to UKBA to let them know, is it okay to email them?