Many people are hesitant to this because they are embarrassed about their feelings but talking to your loved one can really help in this situation. Chances are that they know you better than anyone and can assist you working through these things. They may even confess similar feelings which helps you to realize that cold feet are completely natural.
Talk to a married friend.
Talk to someone who is married and get their perspective. They will be able to assure you that they had similar feelings of anxiety and that there is no cause for concern.