They say that polyamory isn't 'just about the sex', and 'people aren't just 'needs fulfilment machines', but the truth is that I have a very high sex drive and my husband doesn't. I need more sex and sex is better for me when I know and at least like a person. But sex with loving is even better! So basically, the need I'm looking to fulfil with a polyamorous relationship, is sex.
My husband says there's something wrong with me because sex is the primary goal and that I should swing instead. But I don't want that and it's causing fights between us. Is he right?
Short answer. Whilst using polyamory just to get sex is not ethical (and not what it's about), it doesn't sound like this is what you are doing. One of the most common difficulties in a partnership is accepting that the person you feel so well matched with in other respects, has different needs than you do and that sometimes, you can't even understand these needs. In a relationship, it makes us feel afraid of being replaced. I suspect that your husband is on a slippery slope to jealousy...
We are creatures of survival. Our minds have a habit of deciding that if a way works for us, that it must be the 'right' way. As the mind also likes polarities, it decides that other ways are 'wrong'. We all do it, in fact our entire society is built on this premise. But sometimes the mind goes further and decides that the other ways are not only wrong, but just by existing, they are a threat to the 'right ways'. Fights ensue, even wars - well you get the picture.
This 'right and wrong' attribution has been highly successful for establishing and maintaining our species, but it also has the potential to undermine our relationships. Specifically here, the one between you and your husband. The non-violent communication philosophy - that we all have more or less common fundamental needs, but the strategies we use to fulfil them can clash - goes some way to providing a framework to resolve those differences.
Polyamory also provides a framework supporting our different needs. Your husband's spoken concern is that there might be a risk of objectification if you treat someone with whom you are in a relationship, and what More than Two has described as a 'needs fulfilment machine'. I'm not sure that's all there is to your husband's concern which might stem from underlying fears, but that will be up to you to discuss. Yet people also mutually 'use' each other for specific purposes; notably swinging is enjoyed by many to express themselves sexually. And there's nothing wrong with that because the intentions are clearly stated and hopefully understood.
I don't see that you are using people for sex (even if this is absolutely acceptable if you both consent). You are looking for connected sex which occurs within the context of a loving relationship. You want both. And to me, that sounds just fine. Don't buy into your husband's belief that your only goal is sexual - trust your own evaluation. Do try to understand all your own needs without objectifying your partners or making your love conditional. Communicate with all your partners and be happy.