Do I look to stubby and short for it? Does it make my shoulders look too broad? Look in the mirrors too. I'm super worried

My boyfriend invited me to his cousins wedding that is out of state. We will be flying there. I said yes of course but now all of these problems are arising. My question is, as a "plus one," what am I supposed to pay for? I guess my flight yes.. But hotel? Gift of $ in the card?

To be fair I was only quoted 100 bucks for a full night for a wedding. She is an amatuer photographer that was reccomended to me, and I've never actually met her in person, let alone her husband. I feel like it would be super awkward to have him there, especially since she will be there in the dressing room taking photos, but I just feel like it would be super awkward to have him there where no one knows him (not even guests). What do I say if it's okay for me to say no without sounding like a jerk? I just really dont want her to be distracted by her husband being there, especially since it's pretty easy to find someone else who doesnt have to bring their spouse... I feel like. a jerk for not wanting him there