You're not my mother!

Im 2 months post partum and i spent my 1st mothers day with my new baby alone. Because my partner doesnt feel like owes me anytime or acknowledgement because I'm not his mother even though i have birth to his child. He literally posted on social media wishing the entire world happy mothers day but chose not to say anything to me until 8:30pm after he came back from Spending all day with his mother. I got no flowers, no card, no quality time nothin! I spent my night in tears and he still doesn't understand why I'm being so "selfish."