Extremely anxious about sex

I’m a woman and I’ve been seeing this guy for a month and I really like him but the thought of him expecting sex curdles my stomach. I’m a virgin but he isn’t and he’s been nothing but respectful but I know he’s waiting for it eventually…it’s been going well but I’m scared to lose him if I don’t act on it soon. I’m in my mid 20s so I’m hopelessly embarrassed about my lack of sexual activity. Just the expectation, unfamiliarity, and my body image issues really turn me away from sex but I genuinely like this guy and find him attractive I just dont want to have sex which I know is a big dealbreaker for men. How do I tell him this in a way that doesn’t make him lose interest in me? He also knows I’ve never dated or slept with anyone.