Saw you comment on another post about your story so came for a read. It’s good you have put all your thoughts down and realised what’s gone wrong.
Have you both made a plan now of what you will each do to start making things better as it sounds that you were both involved in what’s been going on so it’s not just on you it’s the pair of you going to have to accept your part in it to move forward I think. You will need to work together if you’re staying together rather than just blaming yourself. I think the more you hang on to the guilty feelings the more likely you are to be doing the things you say you don’t want to do. It sounds like you have lots of good intentions to be a good man, you’ve made some wrong decisions but now you have the chance to make it right.
It sounds really positive that you’ve realised how it can affect your daughter and you have that to hold onto, to give you strength moving forward now. Although you say you feel alone you certainly are not, there are a lot of people in the same situation and lots of people on this forum who can chat to you and give you some help and advice or just to read your posts.