How do I tell my partner that I tested positive for HSV???

Recently I tested positive for HSV 2 and I’m kind of lost on what to do. I had sex with someone a couple weeks ago(we used a condom) who didn’t tell me he had it and after we did it he ghosted me and hasn’t responded to any messages. I thought it was weird that he left so quickly so I went to get tested and it was positive. However right before I got tested I had sex with my now boyfriend before symptoms even popped up. I’ve been trying to tell him ever since I got the results but I’m not sure on how to approach the situation because it’s so stressful and I really didn’t know I had something before me and him did it. The symptoms popped up right after me and my now bf did it once for the first time with a condom but I know it’s not from him idk I’m just scared and I don’t know what to do.