If you are able to commit to a dieting plan, such as weight watchers or exercise videos, there are lots of links and information in this forum to help you find what is best for you. My advice to you is to start in your pantry by clearing out the foods that are bad for you and filling the fridge with fruit and vegetables, and then hitting the gym/pavement for 3+ days a week of exercise. I see you have four others in your family, so perhaps you could go to the local swimming pool or visit local attractions/parks and have fun!
What helps me is to think of losing weight as a lifestyle change, rather than wanting to lose weight or diet. That way I know that what I'm doing is not a short-term investment but something I'm going to do for the rest of my life.
Oh, and remember that the number on the scales is not a judge of your efforts. It doesn't know how much your exercised or that you didn't eat that piece of chocolate cake (or whatever is your weakness)!
We are all here to help you on your journey and wish you all the best
P.S. Choose 145 as your goal weight. You'll feel more confident about reaching your goal once the weight starts to fall off!