Longing for second baby

[Misskg1982]

I really need some advise in how to move on from longing for a second....
I have one DD who is 2. Prior to having her I hadn't given much thought as to how many I wanted and we hadn't really discussed having more then one. I don't know why, we just didn't. But soon after having her I knew I wanted to do it again.
At first my OH said "let's just enjoy her first" but as time went on the comments started "I don't want no more kids". At first I ignored it or would say "we havent got to decided that now "as we were in the throws of nappies and sleepless nights. But still every now and then he'd say something. Earlier this year I sat him down and spoke to him and explained how I felt and that I'd like us to try for baby no 2 and he said no. After saying all the necessary things (money, having to move eventually, our age 37/38) he went on to tell me he couldn't think of anything worse then going back to the baby stage and that he wants his life back. As you can imagine I was devastated.
We have had a few conversations since but his outlook hasn't changed and he told me just recently that although he knows it would make me happy he just can't have another baby. He even went as far to say if I wanted to leave he'd understand.
Now I'm not going to leave and break up my family but I'm struggling to come to terms with not having another.
I agree with him it'd be tough with a toddler in tow but it doesn't put me off of wanting to raise a second child. Has anyone been through this? How did you cope with the longing for another?. I find myself thinking about it on a daily basis and some days I get so sad I just sit and cry. Then the guilt starts that I'm not appreciating what I already have. (I must say he has been very supportive during this time and is understanding of my feelings. I also want to add that he is a good dad and does his fair share when it comes to our little one).
How do I move on from this?? Help!