This is not the first time that a relationship has changed because of your drinking. What is great is that you noticed it and are feeling it. Even the pain you are going through is a sign of growth.
Things are different now. You broke a trust and now need to regain that trust. This is what happens when you go out. What took over 4 months to build is not going to be rebuilt overnight. But it can be rebuilt.
It is not the end of the world. It is not the end of this relationship. But it could be the beginning of real sobriety.