Focus on the positive things you are doing for yourself and don't be too hard on yourself. You are here making an effort to make improvements! You should feel proud that you are started making changes.
Identifying sources of stress is one of the first steps in learning to manage it. I have learned so much from the Wellness section of SparkPeople. www.sparkpeople.com/resource/health-and-we
See if any of the articles or resources there can help you.
I would stick with the changes you have already made to your diet and exercise, but maybe work on dealing with your stress before changing anything else, unless it will help you with the stress. Such as exercising - it can be really good for helping to relieve stress. Even just a few minutes at a time and something you can do at home. Give it a thought!