Sorry you feel crap roslily. It is hard to go back, and even harder to do full time, when they are so little.
I really would use your feelings on this to spur you on to talk to your husband about how you feel. If you 'hang' these feelings on mother's day, you will let him off the hook. He will be able to think "oh, she's fussing about nothing".
If you talk frankly about your feelings about how he sees you as a mum, and his lack of positivity about you, then that is not so easily swept aside.
By the way do you praise his skills as a dad?
Sometimes it takes one to start this kind of remark and the other one will follow suit.
On Mother's day, if this were me, I would dress your DS up in one of his loveliest outfits, take some lovely pictures of him, and buy yourself a lovely bunch of spring flowers and just take some time to appreciate how much YOU enjoy being a mum