Re: Read a book ?
It sounds like you're in a very small company and you're doing everything that your boss doesn't want to do....
Perhaps you could threaten to leave again, and stay if he offers you a share of the company (or a profit-share).
Perhaps he could hire a temp secretary/school-leaver/early retiree which would free you up to do a bit of tele-sales, sales, market research, haggling with suppliers, business development. Take your pick!
Or since your company is still small after 10 years, maybe your boss is doing something wrong. Find out what it is and set up your own company to fill that niche! Afterall, you probably know everyone in the business at this stage
Or since you seem to have mastered 'accounts', could you teach it or sell it for another company?
Sluice