Need some advice!!!

I've been with my partner for nearly 5 years, we have two kids together and we're only 22/23. Recently I've noticed my sex drive has just disappeared like seriously, he will be in the mood and I'm like I'm tired🤔 but I think he is losing interest in me now. Anyway what can I do?? We've never really spiced things up because we have kids😂 I've never tried any sexy lingerie or anything because I'm not 100% body confident, any tips??🙈