Dude , stay calm , many people have been through your situation. What happened just happened. I would suggest you to sit and think for some days about what is going on with you, try to understand what you did wrong, most of all. I would also suggest you to get things clear with your girlfriend. Imo , if she does make you feel bad, I would tell you to just get some distance from her for a while , because remember that everything you have in your life is to make you feel good and happy, and not to bring you down. Dont think of your friend and your girlfriend, you should rather be focusing on yourself, because you will lose the most valuable thing in life, yourself. Being alone or feeling alone is not always bad. It was meant to happen for a reason. Personally , I believe being alone is a good situation , but a weird as well , because despite the fact that you feel depressed and sad, it gives you plenty of time to reconsider about everything in your life. Being alone will give you confidence as well , it will make you see things clearer. Being alone can lead you to a situation where you will need to take actions on your own, giving you the opportunity to understand that you are the one in control of your life , and you can do anything on your own, without assistance. See? Loneliness has its advantages as well , which you cant see at the moment , but when you will be out of it , you will understand the positives of it. This period of your life is really bad , but what I can tell you for sure at the moment is that you will get over it sometime.