Re: hubby frustrated
I have to go with Conner on this one. There are soooo many problems in this relationship. She says she'd never had a desire for sex, so I am going to assume he's always known that. If it was a dealbreaker, he shouldn't have married her (if she hid it, or had a strong drive but now doesn't, it would be somewhat different).
Mary, first get off the Avlimil. It's a scam, and some of the herbals in it aren't known as being safe for long-term use. Getting off the billing cycle could be tough, and the company is involved in a large, class-action lawsuit about exactly that.
Next, it isn't suprising that you don't have much drive if your husband is gone 2-3 weeks at a time. Many, many women need ongoing, regular intimacy and contact in order to be in the mood to have sex. This isn't weird, uncommon, or a disorder at all. If your husband expects more sex, he should consider a career (such as an intrastate driver) that would allow him to be home more to help meet your needs so you could help him meet his. This isn't a one-way street. If you're not getting what you need, there's no reason to expect you'd just "be in the mood" to give him what he needs.
As Conner says, he also needs to work on his attitude. I rarely recommend therapy, but in this case I suspect that about the only thing that will help the two of you because you're coming from places so different with these thoughts that you'll need a translator to communicate.
Lastly, if you've never been a sexual person, that may just be how you are. Everyone is different. If you'd once had a strong drive and had lost it, there would be more things to look at; however, as you say you've never been sexual, it may just not be part of who you are. As long as you were honest with your husband before marriage and he accepted it, and as long as it doesn't bother you for yourself (as opposed to feeling you have to be a sexual person for him, which isn't likely to work), it may just be in your programming. If it bothers you, you could look into possible causes (upbringing, religion, relationship, hormones, health & meds, etc.) and treatments. Unless the relationship changes, however, it is unlikely that any of this will help much.