Your hair looks very healthy on that picture! I guess it was somehow humid that day. That's why your hair started to shrink.
Are you sure you are actually pulling the hair out? Maybe it is already lose and just comes out because it sticks to your fingers?
Do you massage your scalp? I've just started to massage my scalp with sweet almond oil and some drops of rosemary oil. I've read somewhere that rosemary oil also stops shedding and helps with growth. Anyway...it is very relaxing.
That's very interesting!