When to tell potential romantic partners?

Hi Everyone, I was moved to tears today because I literally JUST found out that there's a term for this affliction, specific common behaviors and thoughts associated with it, and that there are other people who do it. I started when I was 14 and I am 26 now. I've had periods where it's gotten better, but now I feel it's worse than ever. It used to be my legs but they have healed pretty completely and now I just have a few light scars that I can explain away as chicken pox scars. Now it's just my arms, but it's really, really bad. I can't wear short sleeves, a swimsuit, or lingerie. I don't feel sexy when I'm being intimate with a man. I get so much anxiety and my heart races and I literally feel like I want to pass out at the thought of telling anyone. No one knows but my immediate family, my doctor, and a few of the guys I've dated. They have all been super supportive and loved/accepted me regardless of my condition, but every time I'm single again I freak out because it means I'll have to try to find someone again who will understand and the horrible moment when I have to tell them and god forbid, SHOW them. It makes my own stomach turn so the thought of baring all to someone I want to find me sexy is just impossibly hard. I feel like I'll never find anyone. I'm wondering--when do people typically tell their partners or potential partners? Like how soon into dating them? HOW do you do it? And do you show them or just tell them at first? I'm so mad at myself and I hate this. It's ruining my life and it's been like 12 years. The secrecy drives me crazy. I look at myself in the mirror and I can't understand why I can't stop. I've ruined an otherwise gorgeous body. Outside of this, I live a pretty normal life with a super successful career, lots of friends, very active, and I'm attractive too. Nobody knows what I'm hiding and it's so stressful to think about trying to find someone to be with for the rest of my life given the circumstance... I just want to stop. I'm taking steps to do that, but the scars may never go away completely. And in the meantime, I still have the need and desire to be intimate emotionally and physically; to have a boyfriend/husband, but I just feel so hopeless. And if/when it ever comes time to get married, the thought of not being able to find a beautiful wedding dress or lay on the beach with my husband on our honeymoon is just...devastating... Any thoughts or advice on the sig. other disclosure situation, or even on finding a sig. other who will be accepting to begin with, are much appreciated. I am so thankful I found this community. It sounds silly, but just knowing I'm not alone helps x500 trillion. It gives me new motivation and hope for recovery.