Taking charge

I want to take charge of my sex life but I'm scared to do it afraid my fiance would find me weird. I really wanna be comfortable sucking him and doing new things with him. He's got this thing where he would like me to do it in the shower and I'm just afraid of being to into it will turn him off. He asked me to use my vibrator once but I couldn't do it with him watching me because I feel like I'm being graded upon my work. I would like to talk to him about it but I don't know how to do that without feeling nervous or self conscious. We have literally been together for 8 years going 9 and I still find myself getting butterflies when he's touching me. I will start to do the small things he asks me to do and then I freeze up and say no nvm even though I actually want too easepcially to make him happy and to help me. He never forces me to do anything and I'm extremely happy about that and he's always reassuring me that I'm beautiful in ever way shape form or fashion but in my own head I never feel pretty and good enough for him. I always feel like one day he's going to be disgusted of me. Can somebody help me figure out me....