Sex while prego

Hey ladies, i am currently 27 weeks along and I am so excited for my little boy to be here. At this time I am struggling with my sex life with my husband. He wants to have sex all the time but im feeling so uncomfortable. I feel blessed to be a mommy soon but with my body changing I am feeling bad about my appearance. I know we both are unhappy and left feeling unsatisfied. Is there ways to fix this? Better positions to try as I get bigger, ways to improve the mood? I need help. I want to enjoy sex again..