we need advice on the topic

we will be looking at a story of a young man by the name of Peter (Not real name). He sent in his story and is in need of advice. Find the story below.
Good evening and thanks for giving me this opportunity to share my story and find help. I would really love to get advice because I am confused. My story is one of love and hate.
I have a girlfriend and we have been together since university days. She loves me and I love her too and we decided to abstain from sex until we get married. After I graduated, I served but couldn’t find a job. Sarah on the other hand got a job with a well-paying company. We were still together and things were fine. However as time went by, I became desperate for a job because I felt my life was on a stand still. After staying 5 years without a job, I began to be frustrated. Surprisingly, on one fateful day, Sarah came to me happy and smiling and presented a letter to me. I open it and realized it was an appointed letter in my name. I was shocked! I asked her how come and in response she said she submitted my CV to her boss and he loved it and decided to give me a job. I was excited and my joy knew no bounds. I resumed work two weeks later and my life seemed to have picked up. A month later, I bought a ring and proposed to Sarah. When I took out the ring and asked her to marry me, she started to cry, telling me that she was sorry. I was shocked cos I thought that was what she always wanted. She told me she need to confess something to me. She told that when she took my CV to her boss, he insisted on sleeping with her before giving me the job. She said she pleaded but he insisted and since she didn’t want me feeling frustrated about not having a job, she gave in and slept with him and that she was no longer a virgin.
I was heartbroken. I walked out and have not seen her since then. It’s been one month now and quite frankly, I don’t know how to proceed. Should I end it here or continue with it?
So, what would you advice him to do? Drop your advice and comments and help save a soul.