The Catholic Church has a new pope, but for the first time in my life, he won't be mine.

When Pope Benedict XVI abruptly resigned last month, I made an enormous personal decision. I decided the time had come to change religions and leave Catholicism behind.

I was born and raised a Roman Catholic in England. When I say "raised", I mean baptized, then enrolled in a Catholic nursery school, which led to a Catholic elementary school and then a convent boarding school where, at the age of 11, I was sent for seven years. Like every other Catholic, I made my first confession and communion and was confirmed. At school, I prayed formally every day and attended mass at least weekly until I left at 18.

Some people are believers, others aren't. Some see light breaking through clouds onto a body of water and think "beauty", others think "God". I've always been in the God category. I'm a believer. I can't help it. It's just who I am.

I was happy at school. I was lucky to be educated by nuns who were intelligent, well-educated, compassionate and engaged in the world. They were good role models. A few years ago, they left the shady lawns of privileged private schoolgirls and went to work among much needier people. Their lives are now harder but richer. I know this because I am still in touch with them – 30 years later.

In our final year at school, we studied world religions. This led to the inevitable question of how did we know (how does anyone know?) that our religion was the true one? How could everyone be right? The nun who was teaching us came up with this image:

"Think about a diamond with all its different facets. Those facets are the various religions. If you put that diamond up to the light – God – it shines through every facet differently, creating a variety of beautiful colors."

I loved that image. I still think of it as a critical way of explaining religious tolerance.

If my experience of Catholic women leaders has been overwhelmingly positive, I cannot say the same for our male leaders. Who could? The hypocrisy we have been exposed to has been overwhelming. So has the intolerance. There's a joke currently doing the Catholic rounds that has the three members of the Holy Trinity each choosing where they'd like to go on holiday. When it gets to the Holy Spirit's turn, he says, "Rome – because I've never been there." That's the Vatican's reputation today.

My religion evolved, as I grew older, as it tends to. I was partly Catholic and partly a whole lot of other things, to do with nature and relationships, and being a woman. The church's positions on contraception and abortion were not for me, but for a long time, I felt able to ignore them.

Living in New York, I got married in the Catholic Church. And when our two daughters were born, they were baptized. My husband, who had also been brought up Catholic, had long left the church, but was prepared to come back for milestone events.

It is extraordinarily hard to bring your children up in a community with an entrenched tradition of pedophilia. Everything about it feels wrong. It is almost impossible, as a mother, to stay connected to a church where thousands of children were abused, and the response of the men in charge, those you have trusted all your life, has been to cover the crimes up.

But for more than a decade, I tried. I believed that the number of good people in the church outweighed the bad. I believed in the triumph of good over evil. I believed that the people in the pews around me felt as I did and we had a duty to persevere.

So I took my children to Sunday mass, spent two years preparing each of them for their own holy communion in weekly lessons and joined church after church in New York, hoping to find one that could feel like home. None of them did.

I would give money to the collection wondering where exactly it would end up. Would it pay off an abuser? Get laundered in Rome? Subsidize a hypocritical lavish lifestyle? For a while, I stopped giving, then out of habit started again. For a while, I stopped going to church, too, but I'd always go back.

At the age of eight, my younger daughter began to serve mass, and I was struck that, hierarchically, this was as high as she could go as a Catholic. That felt wrong. But by now, it all felt wrong. I was ashamed of my church. I had not lost my faith in God, but I had completely lost my faith in Roman Catholic leaders. The scandals grew and multiplied, going higher and higher up. Where would it end?

And then, the pope quit. The pope! He left. He walked out on it all. I watched him fly away from Rome and I thought, "That's it." In the few moments of his flight, I left too. I decided I could no longer be a part of this church. It was over.

I realized I didn't want this decision to be about leaving, but joining. I knew immediately I wanted to convert and become an Episcopalian. Why? If I were to trace this decision back, it would be to a summer I spent in Maine 11 years ago. Our closest church was Episcopalian, so I went there on Sundays. The vicar was a woman. Her sermons were eloquent, moving, compassionate and connected to the modern world. She spoke like my nuns.

So, as the world was introduced to Pope Francis I on Wednesday, I watched from a distance, both literally and emotionally. His problems are not mine. I saw the excitement in St Peter's Square and found it moving.

I felt excited, too, but for a different reason. This Sunday, I'm going to an Episcopal church where I've already talked to the vicar. Eventually, I'll be baptized.

It's a new beginning.