Help with being comfortable

So my boyfriend and I have been together over a year now. I’m currently 18 weeks pregnant. I have a 2 year old son and ever since I’ve had him I’ve been so ashamed of my body.. all my boyfriend wants is for me to feel comfortable with him and see me naked.. it’s not that I’m uncomfortable with him I’m just so ashamed with my body and feel so disgusting in my skin it’s hard for me.. very hard.. I don’t want him thinking it’s him tho.. help😭