My boyfriend of almost a year and I haven't had sex, we've tried, but I had a bad relationship in the past and my ex tried to force himself on me. He did insert his penis before I could push him off me, and I was so young. But now I feel like I'm ready to take this step with my boyfriend, he's been so good and patient with me. But every time we make it to bed I freak myself out, tighten up, and stop him. How can he and I get over this?