Spontaneous breakdowns

I had a spontaneous break down in maths today, and it wasn't because of the equations, well partly. I just feel so stupid sometimes and especially in maths because being in the top class, everyone is just really smart and last year I was one of those people and was quite good at mathematics but this year I've just continued to go down hill. I think that this breakdown was put into action because of that feeling of being stupid and because I have this unresolved build up of emotions and just everything that has been going on in my life lately.

I want to be happy again. I haven't been happy in a very long time now and I don't like having these random outbursts in class. I've been trying to take the negativity out of my life but it just isn't working and I'm as sad as ever at the moment.