Being an introvert doesn't mean that you will never find a real friend. World has good people and bad people too. I know how much it hurts when you just want to hug someone and cry and vent but their is no one. That's the time you should find your own company. You would not be alone once you find yourself. You need to first break your thought pattern. Try to avoid thinking that you are alone. No your are not. You have yourself. Start loving yourself and accept yourself. Everything will be fine, you are doing great. You are giving your best that you can do at that very moment. And about your girlfriend if she isn't trying to comfort you even after knowing what you are going through I don't know what type of girl she is. Sorry for being harsh but be careful, not every person who shows us love really loves us. Just don't let her use you. Don't let her break you. And if she really loves you, then you will never be alone. Whatever is troubling you go in front of a mirror and speak about it. Or either record a video about whatever problems you are going through. And then comfort yourself. Tell yourself you are doing great. You are doing the very best you can, You are wonderful.