Hi!!!!
“He’s too big” sounds like a movie, but it’s not a solid excuse for not wearing a condom. Amazon has all the sizes you need.
Your boyfriend is scared, and a scared man can’t “perform” in bed. Even if you “encourage” him, he’ll be thinking, “I’m not going to make a mistake”. All the fun is lost in that stress. Until he gets over the fear of pregnancy, there’s no point in having sex without a condom.
Ask April was right that most people rely on the pill in long-term relationships, but if your partner is scared, it’s wrong to push him.