I think first, never do something you know deep down you don't want to, sexuality is for the both person and in your case it's about your pleasure first and not his (for the moment). Don't feel ashamed of your fears and it's normal to not be comfortable at the beginning!
Maybe your boyfriend should try to "turn you on", with text and his words and how he kisses you and touch you (hands, your body when you two are together)(if you are comfortable about it, of course) to instaure a good ambiance for you. in fact, in your case, it's your boyfriend job to make you feel comfortable enough to have sex with him and not make you feel like you are doing something wrong by making him wait (but i understand your boyfriend, he likes you so he wants to do things with you). If he achieves making you feel comfortable with a good ambiance, then you can let your desire speak

I guess it's having a previous ambiance of foreplay that will make it natural for both of you.
Then, about sexuality and desire, you have to talk about it with your boyfriend. Honesty is primary in a relationship. He will understand you more and you will feel listened to, and you will be more okay with sharing this experience with him. Maybe by speaking to him, you will know that your anxiety is something you need to work on for yourself!
Have a great day