The best advice I have heard on the subject is that you should not have another child until it will not negatively affect any children you already have. This can mean lots of things, depending on the family and their circumstances.
In your case, having another child sounds like it could be a severe stress on your husband, which would be likely to have a negative effect on your marriage and home life, which would certainly have a detrimental effect on your daughter.
If your primary argument for having another baby is to have a companion to your daughter, and that she will feel all alone in the world without a sibling, this is just not true. I had a single, very happy child, who now has a single, very happy 4yo son. Nobody feels all alone. perhaps because they don't expect to. Friends, both young and old, are accessible everywhere. At least half the young families I know have stopped or intend to stop with one child.
One-child families can be happy. And multiple-child families can be very unhappy. Attitude is so important to happiness. Is it possible that you have set your future in stone: you WILL not be happy unless/until you have a second child?
There is always a chance your husband could change his mind if the two of you can find a way to hear and support each other's feelings. The best way to talk to your husband about your feelings is to be sure you are talking about your FEELINGS (always pure emotions like joy, sadness, confusion, loneliness, anger, etc.).
Avoid the mistake of discussing your CONCEPTS (bigger ideas like needing a child, having no one, alone-ness, needing respect, sympathy, support, etc. You can argue endlessly about concepts, but neither of you can tell the other that your feelings should be otherwise.