You need lessons,
I teach 50 students, and I take lessons every week, there is always an aspect to you playing that can be improved upon, especially because the student is not aware of these things untill the teacher points them out.
Self taught playing is fine if you only plan to play for non-musicians, but musicians will definitely notice articulatons, tone production, voicing etc. and who is going to think of those things unless a teacher is on one's case to do so. Also, a teacher is a great motivator, you are wasting money if you don't practice, so you practice.
If you're serious about piano, find a really good motivating teacher and go for it, there's no reason to not go all the way!!
Best of luck..