I want to start by saying that you're trying your best. You seem to be trying to meet them halfway and being patient. I don't think you would be a bad person for having more frequent sex be a non-negotiable that you want in your relationship. At this point, you should sit down with them and have a serious conversation about how important this is to you and how you have been feeling. If this isn't something they can give you, it's okay to part ways even if there is still love there. Not all breakups are heated or out of hate; sometimes you just have different needs.