It's good that you talked to him about it. Don't regret that. As others have said, it's going to take a little time, strategy, information, and old-fashioned sweet talk!
You gotta counteract his resistance with sweetness.... Rant with us all day...get it out of your system, and then when the subject comes up with him, be positive, informative, and patient. Tell him how excited you are and remind him (and yourself) of other situations where he may not have been supportive at first but now it's all good! Same thing here.
Remind him that his support and openness allows you to try new things, and that is what makes him a wonderful husband.... Flip it, baby!
Not to take the thread off track, but this situation is an example of how to work in relationships. I just got this book "The Power of a Woman's Words" from the library yesterday. It listed 25 things NEVER to say to your husband and 25 things your husband longs to hear. Here's the 25 things your husband longs to hear:
I've been thinking about you all day?
What can I do for you today?
How can I pray for you today?
The best part of my day is when you come home.
You are one of God's most precious gifts to me.
Thank you.
I'm sorry.
You are so wonderful.
You look so handsome today.
You make my day brighter.
I don't feel complete without you.
You are my best friend.
I love spending time with you.
Thnak you for taking such good care of me.
You are my knight in shining armor.
I will always love you.
I trust your decisions.
I can always count on you.
What would you like to do?
I prize every moment with you.
I see God's fingerprints all over you.
You are such an inspiration to so many people.
You are such a wonderful father.
You could give classes on how to be a great husband.
I believe in you.