He popped the question, you said yes. He puts the ring on your finger, thus begins the wedding preparation process. As a woman this might be the very moment you have waited upon for a long time, to become someone's Mrs.; to adopt someone's last name. We often forget that there's one person that might have a hard time accepting that you're soon to let go of his last name.
As a kid, it is almost certain that there's only one man you have your eyes on, your father. The one who takes you in his guiding arms, the one who protects you from harm, the one you want your husband to be like. When the time comes however, inevitably there is another man that he needs to share you with and it only makes sense if he feels a little heavy hearted to let you go.
At a time like this it's probably best for you to spare a little time to have a quality time with him to ease his mind. There are some things you can do to have a father-daughter quality time. In the midst of wedding planning stress, spare time to go on a date with him, just the two of you. You can bond over a sharing moment where you tell each other stories, aside from the wedding planning. Also, include him in the wedding planning process. Even though he might still struggle in letting you go, he still wants what's best for you. Show him that you respect him and value his opinions. He will feel accounted for and that will make him happy.
Out of everything, he loves you dearly. Do these simple things and surely it will bring peace about the wedding, especially to him. Happy father's day!