You are a designer. You make invitations all the time. Why not design your own? Sounds logical. The issue with having that much control is the fighting and constant revision. The bride wants one thing, you want another. She wants ornate, you want simple and typographic. This was the only argument we had, so it became a bigger deal than it should have. In the end, we struck a compromise. I would use letterpress to make it seem fancier and I could go simple.
In short, never make your own wedding invitations. Ask a friend to do it.
Letterpress on French Construction Recycled White