Moving sideways, eg to CTO or CSO ("Scientific") or somesuch can be done, and work, at least for a while. But it's tough. My situation hasn't exactly matched

Moving sideways, eg to CTO or CSO ("Scientific") or somesuch can be done, and work, at least for a while. But it's tough. My situation hasn't exactly matched yours, but I think I know that oppressive feeling well! It's not as if you are flouncing out after 5 minutes on the job: you've done a decent stint. I think that you should not let things carry on as they are: it's risky and suboptimal for you and the business IMHO. (BTW, I moved from CEO to CTO for my last business, and that was fine; I'm not a natural CEO!)