Honestly, the pre-nup is just the symptom here. You're clearly expressing feelings that the age and/or income and/or stage of life differences seem to be hurting your feelings of autonomy or making your own way. You seem to be expressing feelings that your life never had a chance to start, and as nice as it is to have an older and established husband to take care of you and provide a really great safety net that a lot of people would really value, you have issues with what you've given up so early in your life.

I think you're ultimately happy in this relationship (based on this short post, admittedly) and ultimately not THAT bothered by the prenup. I think this is a simple case of "cold feet" related to all the stuff you're giving up to be with this person.

It's not exactly advice, but I'm going to link you to the poem that I chose to have read at my wedding. It addresses the concept of things we give up when deciding to marry, and very beautifully states the fact that roads we don't travel will always seem so perfect.

Garrison Keillor: Ode to Oregon Our people aimed for Oregon When they left Newburyport— Great grandma Ruth, her husband John, But they pulled up in Wobegon, Two thousand miles short. It wasn’t only the dangers ahead That stopped the pioneer. My great-grandmother simply said, “It’s been three weeks without a bed. I’m tired. Let’s stay here.” He put the horses out to graze While she set up the tent, And they sat down beside their blaze And held each other’s hand and gazed Up at the firmament. “John,” she said, “What’s on your mind Besides your restlessness? You know I’m not the traveling kind, So tell me what you hope to find Out there that’s not like this?” The fire leaped up bright and high, The sparks as bright stars shone. “Mountains,” he said. “Another sky. A green new land where you and I Can settle down to home.” “You are the dearest wife to me. Though I’m restless, it is true, And Oregon is where I’d be And live in mountains by the sea, But never without you.” They stayed a week to rest the team, Were welcomed and befriended. The land was good, the grass was green, And slowly he gave up the dream, And there the journey ended. They bought a farm just north of town, A pleasant peace of rolling ground, A quarter-section, mostly cleared; He built a house before the fall; They lived there forty years in all, And by God persevered. And right up to his dying day When he was laid to rest, No one knew—he did not say— His dream had never gone away He still looked to the west. She found it in his cabinet drawer: A box of pictures, every one Of mountains by the ocean shore, The mountains he had headed for In the state of Oregon. There beside them lay his will. “I love you, Ruth,” the will began, “And count myself a well-loved man. Please send my ashes when I die To Oregon, some high green hill, And bury me and leave me lie At peace beneath the mountain sky, Off in that green and lovely land We dreamed of, you and I.” At last she saw her husband clear Who stayed and labored all those years, His mountains all uncrossed. Of dreams postponed and finally lost, Which one of us can count the cost And not be filled with tears? And yet how bright those visions are Of mountains that we sense afar, The land we never see: The golden west and golden gate Are visions that illuminate And give wings to the human heart Wherever we may be. That old man by dreams possessed, By Oregon was truly blessed Who saw it through the eye of faith, The land of his sweet destiny: In his eye, more than a state And something like a star.