I like to have my own little way of conceptualising the spoon theory, because some tasks take much more out of me than others, but I am usually able to complete roughly the same number of little tasks per day. For me, I visualise this in the form of teaspoons and tablespoons. On a normal day, I probably have about 4 tablespoons, and about 6 teaspoons.
My pain reached the point where I was actually in tears, struggling in vain to convince myself that I was fine, hoping that if I just told myself to be strong it would go away on its own. Luckily, I have some amazing people in my life who know the difference between when I'm being brave, and when I'm just putting on a brave face.