Praying for you both!
As far as advice goes, be sure to continue to pray for her yourself, and be sure she knows that you still care for her, ESPECIALLY as a sister in Christ!
Also, don't hesitate to talk to God about what's going on with you, about how you feel, and about what you want. At the same time, you need to surrender your relationship with your girlfriend to Him, to His sovereignty and His love, just like you need to surrender everything else, trusting the outcome of all things, including this relationship, to Him (knowing/trusting that He knows what's best for you .. just like you did when you first became a Christian

)!
The Psalmist tells us:
"Delight yourself in the Lord, and He will give you the desires of your heart" ~Psalm 37:4
That is an amazing verse, yes (a commandment with a promise), but be careful to take the time to truly understand what it's saying (because it is
easily misunderstood). Verse 4 admonishes us to "
delight ourselves in Him", to chase after God and His Kingdom
alone 
When we do, He promises us that good things will follow, that He will give us our heart's desire (of course, when you truly, "
delight yourself in the Lord", your desires tend to change a bit

).
Yours in Christ,
David
"Seek ye first the kingdom of God, and His righteousness;
and all these things shall be added unto you"
Matthew 6:33