Not the OP but I know that feeling of one's skill as a musician plateauing. Your feeling of "so what now" is exactly the thing you need. When trying to acquire any skill, practice alone doesn't cut it, you need a practice + feedback loop. The feedback is what your "so what now" feeling is supposed to address. Feedback can be external, i.e. coming from fellow musicians or a teacher or internal i.e. you reflecting on how you can get better. Practice needs to be continuously altered according to feedback. To get better you'll need to practice better, also known as deliberate practice.

You'll need to try and push the envelope a bit, go busk and people will give you immediate feedback if something sucks. This will not be a gradual process, days of nothing clicking will be followed by a day when everything clicks into place, keep at it. Playing an instrument should feel like talking to a friend, any awkwardness is something you need to work on, that is the easiest way to get feedback on what needs to be added to you practice regime.

For me the same mental framework works for programming, or any other skill. As it turns out, trying to learn a musical instrument teaches you a lot about learning in general. For that alone it is a worthwhile endeavour :)