If I am understanding you properly, you have already decided that you want to tell him, and you are hoping for support that that is the right decision. I think that @Earthgirl has given you everything you need to understand that it is the right decision, and that it could have undesired consequences—something you already know.
I would like to echo what @Earthgirl said. If you are going to have a truly intimate relationship, then you have secrets about things that are really important to you. Your boyfriend will never really know you if you don’t tell him this story, and clearly it is a very important story for you to tell. It is something that means a lot to you and you have probably learned a lot from.
The question, in my mind, is not whether to tell the story, but how to tell it. I once decided that I had to tell my wife the truth about what was going on in my life because I was fucking miserable. Actually, it was even worse than that, but I didn’t know how badly off I was at the time. I just knew that I was miserable and I felt like we weren’t living in the same universe and I had grown desperately lonely.
I did what many people probably do, and we all get judged harshly for it. I fell in love with someone who wasn’t my wife. Actually, several someones. Now I met these women on the internet and so there were never any physical meetings with any, save one.
The one I thought I was truly in love with, however, was not the one I met in the real world. She was, I think, crazy in many of the same ways I was crazy and we were both desperate. She no longer felt loved by her husband and I no longer felt loved by my wife, and I think that, after we broke up, we kind of grew to truly care about each other. It taught me a lot.
But I was scared about what I was doing. I felt so desperate and I didn’t really think I recognized myself.
I ran over and over the story in my mind and one night, after the lights were out, I started telling it. I did not start out by saying, “I’m in love with someone else,” or “I’ve been cheating on you.” Those aren’t stories. They are interpretations. What I think you need to do is to tell a story without interpretations and let him try to figure out how it makes sense on his own.
Somehow, you ended up as an escort. No doubt, one thing led to another. We all know that. The devil is in the details.
I was just explaining to my kids about Joseph Campbell’s idea of the Hero’s Journey. In short, the hero is kicked out of home for one reason or another, goes on a journey, meets countless tribulations, overcomes them, and then finally returns home, bringing a boon he has won on the journey. The boon can be something physical (gold) or intangible (wisdom).
Your story (as all stories) fits right into the formula. For whatever reason (and you should spend a good amount of time describing this), you ended up in a situation where you needed to figure out how to keep your head above water. Most likely you were kicked out of the house and had no money, but you also could have gotten into it via a different route. It doesn’t really matter what the route is. It does matter that you tell this part of the story very carefully, because this is where you earn forgiveness (and of course, it is forgiveness that you want from him).
How did you get into being an escort? Now what happened before that? And before that? That’s where you start. Before the part before the part where you got into the profession. Hopefully that part will have a lot to say about your relationship with your family of origin and the struggles you were facing that ended up with you doing that work.
If you tell it right, he will see where you are going long before you get there. It will be inevitable. We all know how the hero must fall. How they must be cut down to their knees and perhaps even face death before they can start their way back up.
Once you see in his eyes that he knows what is coming, then you can start talking about it. But no apologies. Not ever. This is you, and it is a part of your that you are proud of having overcome. You would not be the person he loves without this experience. If it works out right, he’s going to tell you he knew before you even said anything.
I’m going to jump ahead to the end now, because this is the other crucial point. It’s what I just said: you would not be who you are (and you would not be the person he loves) without that experience. You have won something in this journey. I don’t know what it is, but you do. You have probably earned some wisdom that few of us will know (and would make you a good jelly should you decide to stay and if you can put up with the suspicion some people will have of you because they don’t believe your story). This lesson you have learned—about how you got into the business and what it took to get out of it and to put yourself in a place where you could have this love—is what he needs to understand and believe in.
He has to find out that he could not have loved you without your past. That it gives you something that other women don’t have—something only he is uniquely positioned to appreciate.
That’s how the story goes. If you tell it right, there will be no question about your relationship. It will open up new avenues of communication between you. You may cry together. You may ask forgiveness and say you wish you told him sooner, and he may say there is nothing to forgive and he is astonished you trusted him enough to tell him so soon.
My wife forgave me in the end. Not right away, but after a long time and a lot of work. But forgiveness actually turned out not to be the biggest thing. It turned out that she saved my life. She listened to my story and she realized that I was not right. I was not her husband. She took me to psychiatrist and I was diagnosed as bipolar.
I know what I know because of my confession. Yours will, I hope, turn out the way you want it to, but you have to trust that even if it doesn’t turn out that way, you have to go through this in order to learn how to open with the guy you eventually end up being with. Whatever happens, this experience will be good for you—maybe not in the way you thought it would be or you wanted it to be, but it will be good.