I need help

(15 btw) So I've been in a relationship with is amazing guy for 6 months, I love to absolute pieces he's my world and I don't know what I'd do without him he's perfect! I've never seen a flaw in him at all until now, I was at his house the other day and We tend to have lazy days where we lay in bed and watch films and the other day I fell asleep, I woke up and he was fingering me... In my sleep? I didn't want to say anything or confront him about it because quite frankly confrontation scares me so I pretended to still be asleep, he was going for a good 10 minutes and then he stopped... (We've had sex plenty of times before) It's really thrown me off everything and I'm starting to see him in a way I don't like.. This isn't normal is it? I really felt like I can't trust him and I feel really uncomfortable about it.. What should I do? Is this normal? Am I overthinking things?