So this is probably really stupid and easy to fix but I'm not sure what I've done or what to do.. I like to build a nice small house in creative mode so i have somewhere to start and not die before having a home. I did that, and i gave myself one or 2 tools to start off with as well. Then i swapped into survival but i can not do anything almost. I can't place blocks, I can't mine anything, I can't eat anything, I can break absolutely nothing.. All i can do is open chests and sit down in stuff like minecarts and get back out and open doors and gates.. That's it..

Does anyone know what i might have done or how to fix it ?