Worst case if you don't have a milling machine, get a mesh bag of some type, blend your grains in a blender, put them in the bag and mash that way. A Brew In A Bag bag is best but really any mesh bag will work, cause I'm assuming your mash tun problem doesn't have a proper filter on it to stop grain getting into the boil.
You're going to get this, and now in 2-3 years when the next newbie comes along you have a story to tell about your learning experience.
Edit: I'd be really curious what the rational from your friend was on not crushing the grain, I've never seen that in any literature or instruction.