Don't grieve alone; 13,000 members and growing
Jordan, I think you got it right when you said you have not yet opened up to anyone about your feelings of immense grief, your self-harm, and worthlessness. You are a precious person who has covered your pain by hiding it to everyone. But you harm yourself by keeping it inside and you see it. You really need to seek out professional help from someone who you can be yourself 100% and tell them everything you are dealing with. Friends and family can only help so much. I can be very open to my therapist and he keeps me focused and gives me an awareness of my issues that I could not get from others.
Please get help, and if the first therapist/counselor is not a good match then keep trying. You are so young and there is much of life to be enjoyed...even though you can't realize it with so much pain you carry.