The problem isn't ideas. It's putting the phone down and picking up the drawing tools.
I'm quite literally in no position to criticise, but I'd like to brainstorm some ideas with you. I struggle with this too, but have managed to make some progress over the years.
Do you take notes for work or something where you could scratch out a concept or two in between tasks? Would an app/phone timer like Lock Me Out help get your phone time down to a level you're happier with?
This kind of stuff has worked for me anyway. Not to say it isn't still a challenge