I'd like to join Tony WK in welcoming you here, it's a good move as sometimes it is not possible to judge oneself with clear eyes, it takes someone else. You are not to blame, your feelings are real, and you are pretty brave in talking about it all - I'm glad you came.
Forgive me if I summarize what your life is like in a few words. I know it is a huge part of your life but want to try to list the things
You feel sad, you feel unhappy, you cry and it is taking over. Because you have heard such feelings come about for a reason you can identify, such as trauma, and you can see no reason you get to the stage of blaming yourself, of feeling guilty, of thinking it may be all for attention and you are simply a bad or less worthy person. You even doubt yourself so you wonder if you are faking.
It simply does not work that way, I had everything one could (reasonably) want in life and yet I followed the same path. And if you looked in some of the other threads here you will find there are many who "have it all", yet cannot enjoy or fall into despair and hopelessness or are simply feeling lost.
The feelings you have are real and need to be dealt with so that you can enjoy a happy life - yes there is one out there as I found.
I could not fix myself, I simply kept on getting worse, and actually left things too long which made matters worse. I did get a lot better - as I am now, but it took medical help, plus support at home.
Can I suggest the first step is to tell someone who can do something about it? Now that might be one of your parents or other family member - what do you think? Maybe you get on well with your mum and can try to explain to her. She may not understand fully but it should be enough to get you in to see a doctor, which is a start.
If nobody at home is OK how about school (I'm assuming you are at school or uni)? It could be a councilor or favorite teacher you have come to trust.
If you want to openly talk or web-chat to someone who is not connected with your life I'd suggest the Kids Help Line, (1800 55 1800) or
They are pretty good, you can go there more than once and that are realistic and will understand exactly what you are going though.
You know you can come right here and talk as often as you want, or browse around the Young People Section which you are in now and see if there are others in your situation you might like to talk with