Relationship advice?

Me and my boyfriend are freshmen in high school. We are very sexually comfortable. We’ve been together about a year and a half. Recently he started fingering me and I was totally down for it and it felt great. What I’m worried about is he’s gonna ask me to give him a handjob or a blowjob. And I just don’t feel 100% ready for that. I’m very paranoid about it. He would understand if I said no but I feel guilty