you've gotten great advice here.. i'm just gonna add to it.
regarding husbands - hate it, but men DO need intimacy. it's in their genes, it's in their gender make-up/requirements (generally - you'd gotten a response to one in a zillion that doesn't). just remember this: if he doesn't get it from YOU he's gonna get it somewhere. adult entertainment, a 'friend', you get the picture.
that said, i suggest you get creative in your participation :) my husband, as is typical, wants <ahem> 'it' more than i do. however, in my attempt to be 100% wife but also 55% not that into it LOL, i use other means approx half the time. couple things to consider: first of all, if you REALLY time things out, your average 'act' only takes, about 4-5 minutes. ANYONE, i don't care who you are, can sacrifice 4 or 5 minutes for happiness in a marriage. trying to get out of spending this precious time with your husband (it's precious to him) takes 20-50 times that amount of time - worrying, stressing, watching your actions so as to not give false promise to him, trying to rebuff his advances, etc - to avoid the 5 minutes! thats just crazy! just imagine how many grey hairs and wrinkles you're saving up for just trying to avoid that 5 minutes? ;) second thought: get creative - when i'm not so much into it, i'll resort to personal 'attention' that doesn't involve 'me' per se, but involves only one appendage (upper appendage, mainly only the one with digits LOL ). he's happy, i'm happy, and truth, sometimes it revs my engines. soemtimes. then we both get 'happy'
he's insecure BECAUSE you don't want him. your refusal equates to you not loving him.. that's just men. hate it, but it's the truth.. he wants you to act like you did when you met him and couldn't keep your hands off him (ya, ya... we've been there too. we know.. LOL)
my suggestion? give him what he wants at least 2x per week. if you think working full time with a small child is hard WITH a husband, try it without. if you don't change your actions, that just might be how you are going to have it. sex is a small price to pay for a companion that loves you. loving husbands are a priceless commodity.