Sounds like you need to have a serious tête à tête with your partner. njl has some great points, but if you are miserable then you might want to consider delega

Sounds like you need to have a serious tête à tête with your partner. njl has some great points, but if you are miserable then you might want to consider delegating the work to someone else while maintaining the project. It really doesn't make sense to work for yourself if you're not.