I've been playing for thirty years and never learnt any theory whatsoever until a few months back when I started lessons. I am now doing the same as you, learning scales and arpeggios. These have been available in a variety of forms for years, obviously, but I think, personally, I need the motivation of a teacher otherwise I feel kinda overwhelmed by the amount there is to learn potentially. Also my teacher allows me to decide what direction the lessons take and I'm finding I'm applying it in my writing. I can wholeheartedly recommend being taught regardless of how long you've been playing, it's been a real eye opener for me.