Yesss, i know what you mean.
I guess i just want to get in to the army so bad, i've trained hard enough and waited long enough.. So i just went into panick mode, i dont want anything stopping me from getting in.
Hey listen, we've all imagined we've got cancer or something equally serious in the wee small hours. Try not to stress too much, its probably a pulled muscle or something dead fixable ok. You're not a doctor, so let a proper doctor look at it, reassure you its probably nothing, rest it for a couple of days, rub this on it and take a few of these anti inflammatory drugs and it'll be fine. Then you'll feel a twonk for having wasted lots of negative mental energy on it eh! See doc, let us know what he/she says and then crack on and enjoy your time in the service .... Good luck, and stop worrying.