First off welcome to the boards! One of my main reasons for losing weight is so I will be healthy enough to have children and be a good role model for them in the future. Your goals are VERY attainable, and I want you to know that you NEVER need to give up on yourself. It's going to take time, there will be setbacks, so set small goals for yourself (i.e. 5-10lb goals at a time) and go from there. Just know that great changes happen over time, so stay consistent and get all the support and advice you need!
Check out some of the groups on here, join up in the challenges because they are fun, you meet others in a similar boat as you, and they keep you accountable. There is a Biggest Loser challenge starting up, new year's challenges, stuff like that. And once again welcome! You can do this!