You do realize you've given enough details to be fully identifiable by your co-founder and probably some others? Anyway, I think the major problem here is that

You do realize you've given enough details to be fully identifiable by your co-founder and probably some others? Anyway, I think the major problem here is that you think you can't say the exact same thing you typed here to your partner and then resolve the issue. You may be right about that, but from the post we can't draw any conclusions. If you feel this bad about the current state of affairs, you should be able to sit down with him and explain (without making accusations, because you are definitely also to blame for having letting it come this far) how you feel and how you think the problems can be resolved. If that is not possible, then the question is: why not?