OK, slooooow down and take a couple of deep breaths.
No matter how old one is, breaking up doesn't get any easier. Depression is a normal part of breaking up because what you once thought of as a clear view has suddenly fogged up. You're going through the first steps and those are the ones that hurt the most. Letting go of someone is the hardest thing to do, be it a friend or a spouse. The two of you shared something that was very special to you and now it's gone.
When I was in college (waaaaaaaaay before you were born), I started going out with this guy I met at an ice skating rink (of all things!). We hit it off immediately--I had never felt anything like this before and he was The One. We made plans to marry five years to the day we met but over time, things started going downhill. I knew the breakup was coming but when it did I was still devastated.
As I left his place for the last time, despite my anguish, I made the decision that I was never going back to him again. I kept my promise but I still didn't feel any better. I thought about him a great deal and all that brought was pain but I couldn't stop doing it. He had become a habit and I had to break that habit.
So, what did I do?
1. I cried a great deal and I certainly didn't sleep well for a few months. When I did sleep I would dream of him and break out in a cold sweat.
2. I kept a journal and poured my heart out to it every day, sometimes more than once. Over time, as I read it, I could see that things were getting better. The rate was slow and I didn't realize how far along I had come until I looked back.
3. I was fortunate to have a support system of both male and female friends and I called in my chits. They were all extremely sympathetic and helped me through some really black times.
4. I reconnected with things I had put on hold and made some new connections to help fill the time. Filling up the time with new things meant I had less time to think of him.
5. When I found myself thinking of him I did what I could to drive the thought right out of my mind. It was difficult at first and took a great deal of effort but I did it. I would think of anything else I could, mostly about getting past this bump and having things turn out better.
6. It sounds crazy, I know, but you have the power to do whatever you want with your life. You've come to a fork in the road and it's up to you to decide which way to go. You don't have to commit yourself to a particular path, just take a stance and follow it. If it doesn't work then go another direction.
The biggest thing is that you have to take care of you for right now. She may not come back and you may as well prepare for the worst.
What would you tell someone who came to you with this problem?
Good luck and do keep posting.