Devious: This reminds me of my last relationship. I am an ex-tomboy, but still not very "girly". (No makeup, hate shopping, have only a handful of shoes --NO HEELS, value comfort over looks, won't do 100% of the housework, pays 50% of the bills, etc.) My ex's family said I was a "feminist" and I remember getting plenty of comments from people that I'd be sooo pretty if I only wore makeup, soooo sexy if I just showed more skin or wore high-heels, sooo cute if I did such-and-such to my hair, sooo attractive if I only lost some weight. Screw that! It only made me want to be MORE boyish. I started wearing men's clothing and cut my hair really short. Even as a child, I was really un-girly. I refused to wear pink for YEARS as a kid, and only willingly began doing so last year!! Although I'm less tomboyish now, I'm still not girly, but luckily my better half likes that.
I don't think your husband necessarily wants to change who you are, but maybe he thinks that you're looking a bit tired and run down and thinks that encouraging you to dress up would help in that area. He may have just been trying to be helpful and not hurtful, even if that was the end result. Sometimes our guys are a bit clueless (just as we can be a bit clueless with them). Anyway, you guys should have a talk about it. Tell him that you appreciate his fawning over you with all the new clothes and dresses, but that it made you feel bad. Also, explain that dresses come in different SIZES

and cuts that flatter different body types, and that selecting makeup is not as easy as picking up nice colors because you have to factor in eye color, skin color, and hair color, as well as what time of day you plan to wear it. And if makeup is just impractical for you, then tell him so! I would hate to wear makeup while chasing after a child! I touch my face so much, it'd smear even if I wasn't sweaty and exhausted.

A good waterproof mascara is about the most I'll do, and that's only when I'm going out. If tinted lipgloss counts, I wear that, as well. It takes me less than 5 minutes.
I think you two should try to compromise. You wear more form-fitting, figure-flattering clothes, BUT he also has to dress up a tad, as well. Or maybe do more around the house. Just, don't change for any guy. If you're gonna change, do it for you!