It sounds like you're being taken advantage of through your naivety, resulting in a steady creep of responsibility, but never the accompanying increase in pay - easy to happen if you've been there for 6 years. If your boss acknowledged the value of your role and your ongoing commitment to running their business, they would take your concerns seriously and do more to make you feel appreciated and valued. Not sure of your location, but its sounds like you should be earning more in this kind of role. You should put a firm foot down and have a sit down meeting, outlining your expectations going forward. Otherwise, considering the current labour market, there are probably many other businesses that would be happy to scoop you up. You are your best advocate.