I went on DofE yesterday and Friday and on Friday Night I picked up my bag to put in the tent and my wrist did a massive click and has hurt from then on. We had to walk this morning and it was so sore all the way. Now it has got worse- it has never been like this before so I am feeling a bit worried. I put a bandage on it but it hurts so much. Could someone tell me what they think please? I'm 13

I don't know DofE, sorry.
But it sounds like muscles/tendons caught on a wrist bone and maybe a bone moved out of place, sort of like a dislocation or hyperextension. A clinic should be able to fix it in a flash, unless something broke. We can't tell, but why sit there in pain? Have you told an adult? Do you think everyone will call you a wuss? Say you think it's broken and don't let anyone touch it. Are you out away at some camp for the whole weekend? It doesn't matter. They have to deal with medical emergencies.