This is a good post you have written - you are clearly no fool. And you have coped with some difficult stuff in your life - that is an achievement. It sounds to me as as if your difficulties at school and in life are, understandably, undermining your confidence.

Now that you are 16 and therefore soon to be a fully paid-up adult you might like to consider how you can help yourself and rebuild your confidence.

I wonder if you can go back to the school psychologist and ask her to go through the options again, and perhaps take a more considered view of what is on offer?

Are your parents aware of how you feel? Perhaps they can help you get some support and treatment.

You don't sound like a 'lost cause' to me. Good luck.