Dear Confused…
These days, self-publishing first isn’t the interest-sinker it used to be with editors. If a self-published books does really well (say, selling 30,000-40,000+ copies) then it can impress editors and spark interest. Huzzah for that, of course. But if it hasn’t sold well (which is, honestly, more often the case with self-published fiction than not) but an editor likes the book and thinks she has a bead on its market, the editor will acquire your book and just have you remove the self-published edition from the market. So no, self-publishing with less than stellar results wasn’t shooting yourself in the foot. Your friend is right: Submit.
Happy writing!
The Editor
The publishing world can be scary and seems to naturally introduce doubts. I’m currently preparing the material I need to send in with my submission of my first manuscript. It’s taking quite a long time and whilst doing it, two of my other pieces have been unsuccessful in a competition I entered, which has caused me to doubt my manuscript.
Great advice by The Editor though, as always. I wish you the best of luck with your writing and career moving foward.