My (32M) wife (30F) got pregnant by a sperm donor against my wishes. Do I raise the child?

My wife and I have been married for 8 years. We dated for a few years before getting married. We were in school for the first few years of our marriage. After finishing school we tried to have kids, but it didn't work. My sperm was tested and my motility and morphology were on the low end. We tried IUI three times and then we tried a round of IVF which didn't work. She was upset and worried about running out of time to have a child. My wife told me she wanted to use a donor. I said I was opposed to it. She went ahead with it anyway and on the second try it worked. Now I feel conflicted. I don't want to raise a kid that isn't mine. I wanted to keep trying to have a kid together. Should I stay with her and raise the child? I love my wife but this feels like a betrayal.