You're getting a lot of Y T A, but I think NAH. Unless you go through with it now that your husband has raised objections, in which case Y T A.
You are not the asshole for wanting to support your friend's dream of becoming a mother. It is a selfless thing to do, and commendable. I do think that the way you talk about the experience of being pregnant to be a little odd, almost as if you desire the positive attention or "respect"(?) it garners you? Most people I've met do not talk about pregnancy that way.
Your husband is not the asshole for not being okay with it. I do not agree with him considering this cheating (and that stuff about carrying "another man's child" is not great...), but if he has a right to be uncomfortable with you being a surrogate even if his reasoning is not exactly stellar.