Like some posters above, I would urge you to get counseling. And you need a very competent counselor. There are reasons why the attention you got from your half brother seemed so very special to you, despite it being a case of a grown man exploiting a minor. You must have been awfully lonely, and it sounds like you still are.

I totally believe you that you are heartbroken and that your life feels empty. I'm guessing that there were other serious problems in your life before the affair with your half brother started. So you've probably been dealing with more than you can handle for a long time. There should be help available to you, even if you don't have money to pay for therapy. What your brother did was criminal, regardless of how much you think it was what you wanted, too. There are incest-survivor support groups on the Internet that might give you a place to start. I know that is not the category you see yourself in. But you are not the first victim of this kind of exploitation who thinks it was totally consensual and not something for you to complain about.

When you don't feel properly loved by anyone, any kind of attention can feel wonderful. You are in great danger of ending up having more relationships that will be very hurtful. As bad as you feel now, I'm afraid it can get even much worse for you. Look for help now, before that happens. You might ask your doctor to refer you. You don't have to go into details with the doctor. You can just say that you are very troubled emotionally about something extreme that happened to you at age 15/16. Sometimes "Planned Parenthood" clinics have counselors who will talk with you about any problem, not necessarily related to pregnancy. I'm just trying to direct you to a place to start.

I hope you find a wise and understanding person to help you sort out your life. It sounds like you must be very alone.