My strong suggestion to you is that you get support and help from other people who have been through this.
I am perfectly sure that you are still very nice to look at and you are still a sexual, sensual being.
Your nerve endings are all over your body, not just in one breast.
I like to think he would have coaxed you into bed as soon as you were physically fit and showed you, by his desire and your response, that it is perfectly possible to pick up your life as a sexual being, even though a bit of you is missing.
I'm not underplaying the loss of a breast – I'm a woman, too, I know how important and fundamental they are – but there is no happy future until you learn to mourn and accept this loss. What gives me hope for you is that you know you are attractive.
I'm assuming that the man you want is kind, enjoys your company, is somebody you can laugh and talk and relax with, is mature enough and has enough life experience to know that he wants a woman who is more than the sum of her parts.
The art of making another human being feel good about themselves involves heart and soul and intellect as well as being nice to look at.
Take a deep breath and really look at yourself in a full-length mirror, making a conscious effort to see the whole woman in front of you, not just a scar, because the whole woman is what other people will see.
But I don't think you need to go through all this on your own.
Then it comes up (I run a male breast cancer foundation), and I get the “Oh,” followed by silence — or worse. I guess that could be a good start for a friendship, but I really don’t know anymore. Why can’t I just pass a note to a girl with the question: “Do you like me? But it’s a tough job keeping track of what you’ve said, and tougher living with whatever it was you said. As I sit here wondering what else has changed after my cancer that may affect my dating, I realized that the only thing that has really changed about me is that I no longer have pecs and nipples. I can get reconstructive surgery to get them back, but I’d rather keep exercising and regain them the natural way, and that is taking some time. Maybe instead of a nipple, I’ll get happy face emoji tattoos. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.