Dont know if i can do it :(

so i gave birth to my son (second baby) 19 days ago and i am dreading when the time comes that my partner and i have sex :( i dont want him to see me naked and i know that i will be thinking about how gross i look the whole time, i really dont know if i can do it, ive even told him id go without until i lose the weight but he keeps telling me not to be silly and he loves me for me but it doesnt stop me feeling insecure :( what do yous do to help boost confidence?