you will have better success if you totally avoid anything white - starch, sugar, rice or any refined flour. replace these items with high quality proteins. make sure you don't lose too much weight too soon, or your body will think you are starving and turn down the metabolism. 10 pounds a month is prudent. there is no escaping the need for daily exercise sufficient to elevate your pulse and make you sweat, at least 45 minutes daily, for aerobic benefit. start by walking at a brisk pace wearing high-quality walking shoes with abundant cushioning. it is almost never too cold or hot to walk. if it is icy or on fire outside, you could invest in a manual treadmill- these are between $100 and $200, do google product search to find the best at the lowest price. some folk swear by rebounders but if you have SI joint problems they are not the best choice.
muscle-building exercise creates a virtuous circle where you have more calorie-burning muscle while building more muscle, up to a point. pushups are a great all-round upper-body workout, start with just one, making sure your body is straight from head to toe during the whole pushup, harder than it sounds. do them whenever you are cold, they will warm you up pronto- do 'em before you start walking, to warm you up.
hope this didn't scare you, but i wouldn't blather on about it unless i did the same things myself. which i do.
good luck