I understand what you are feeling right now; many years ago, when I was a young man in college, I went through a similar experience.
But God knew what was best for me (and for the fine young woman to whom I was almost engaged). Later I would meet Ruth, the woman who has been my wife now for over 60 years–and beyond a doubt she was God's choice for me, and I for her. I thank God every day for bringing us together, and for keeping us for each other during our early years. I often think of the Bible's words: "He who finds a wife finds what is good and receives favor from the Lord" (Proverbs 18:22). How true this has been!
Yes, this is a very painful time for you. But my prayer is that you will turn to God during this time, and commit yourself and your future to Christ. God knows what's best for you, and years from now I believe you will be able to look back and thank Him for leading you to the woman He has chosen for your wife. Seek His will for your life; His way is always best because He loves us.
The Bible says, "Commit your way to the Lord; trust in him" (Psalm 37:5). Yes, that's hard to do when we are almost overwhelmed with pain or grief–but God never fails, and He can use these times to draw us to Himself.