Elbow Pain Help - PLEASE?

hi, having elbow pain for two weeks, being woken up from sleep and everything! It is right on the elbow bone, went to physio this morning and she said near growth plate on the bone beginning with 'o' haa (Quite a long word, don't remember what she said) Anyway, she says i need to get it x-rayed just to be sure it isn't broken.. I have no idea what caused it but i am a keen swimmer if that has any relevance, I am growing at the moment so apparently my bones are quite weak and also It got locked and made a kind of cracking noise to straighten and started hurting since then... It hurts to touch it, even lightly, I can't swim at all, It is waking me up in the night.. and if I try and lean on it.. WHICH KILLS. - it feels like my bone is slipping! - IT IS HORRIBLEEEEE!! Does anyone know what on earth this could beee?????