I am so sorry about your father, that is tough! It is awesome that you want to donate one of yours. Perhaps this will be the motivation to get you healthy as well!!! Your BMI should really be between 20 - 25....with 25 - 30 being acceptable but not as good.
Try and eliminate the "white" food from your diet....refined carbs like sugar, white flour, white rice, potatoes, white bread, white pasta. Try and cut out deep fried foods, fried foods, fast food and junk food.
It is a tough thing to do. I know!! I was a sugar junkie, a coke addict (coca cola!) and a lover of the fast food burgers n fries!!! It was very hard giving it all up!! But it can be done, with the right motivation and you have the best motivation EVER!!