It's normal to be nervous and overthink things, but this is one decision you need to do right or not at all.
If you have someone you trust to talk this over with, do that. No one flighty, but someone older and wiser, who grounds you. Think about why you agreed to marry him, and whether it was because you wanted more of the same, or whether you think he is at his core the man you will love forever.
No human is perfect, and you will find that everyone has something they won't do. What about the other things- does he look after you when you are sick?, does he do things so your life is easier?, does he love you more than anyone else on earth?
Not taking pictures doesn't sound like something that is crucial to life. Why won't he? A lot of people won't take pictures- does he have something to hide, or is he self conscious about his looks? Big difference.
Look at the whole person, and how you feel about that whole person. If you are still having doubts, talk to him and tell him if you really feel you're not ready. If you aren't able to talk to him about this, you're really not ready to be married.
But make sure this isn't just cold feet, because that's normal. No one is perfect, so don't think you're going to find someone who is, but don't marry him this week if you're thinking of him as second best - HE deserves better.