You are depressed, and really need to get some help with this. Depression manifests itself in many ways, and you have many of the symptoms. Find a psychiatrist who you can talk with, and get on some medication to help you get through this time in your life. If at any time your medication isn't working, don't just stop it, or continue feeling bad, immediately get back in touch with your doctor. Sometimes it takes trying different meds before finding the one that helps you best. You're not alone, there are so many of us dealing with this, and we all understand what you are feeling. But life is fleeting, and you've got a lot of life to live. Don't waste another moment of your life feeling this way, get help, and get on with what I'm sure will be a wonderful life. Re-connect with your friends and if need be, tell them what you are dealing with, you may be surprised to find that one or more of them is dealing with it also, and I'm sure they will support you. I know you feel lost and abandoned, but the world is wondering where you are!
I know what you are going thru. I stay in my room. I go see my pdoc/3 wks and therapist/2 wks. I take welburtrin and celexa and trazadone for sleep. Since taking welbutrin I have a better outlook. Hope you can get some help, you are not alone. Good wishes!