True love does not die. Do not beat yourself up for loving her. You need to think before you speak if you do decide to say, the "I love you". But I would share those words in an endearing way so that it does not make her uncomfortable. Michele techniques suggest not to over-pursue.
I'm proud of you for remaining sober. It wasn't easy, owned up to the problem. That took courage. Also, it is a blessing that you both work together to benefit the kids.
Not all women disrepect men who make themselves too vulnerable. In fact, women LOVE to talk about feelings. Words of affirmation is a love language. In your situation, please use caution. The usage of appropriate words, and time is key.
Your other choice is to hope that her new realationship comes to an end. In the meantime, be her loyal friend, and the best possible father.
You may not have all the things you desire. But, take time to use your wisom and heart to take the next step.