My suggestion is make it top priority to find other like minded devs to partner with you in exchange for stake. I'm an investor but I don't think you'll be successful working on a closed source project all by yourself; nothing will get done in a reasonable time-frame. I didn't invest anything I can't lose but I'd like to see something come together to shut up the critics.
One talanted and devoted dev is already almost a miracle
There's no chance to find anybody who would actually help instead of pulling back.