Paracetamol (especially 40) won't do anything for a bad stomach ache and believe me I know because I was born with only half a stomach! What you should have taken is NOTHING! You should have had a glass milk (warm milk is better than cold) and a piece of toast! Then have a lay down with you stomach pressing against the bed, sofa, or just the floor!
I don't know what you could do... maybe talk to him and see where it goes from there!
But please don't take 40 Paracetamols again because you could kill yourself! And I am sure your family don't want that to happen!
Please don't take my post the wrong way, I am only giving you friendly advice and I dont mean to upset anyone if I do.. And I am sorry if I do!
Ryan X