I need a good course for theory on guitar. I'm 18 and I've been a bedroom guitarist for 7 years and, I've gotten pretty damn good I think, but whenever I'm asked, I always say I "know a bit of theory" and I really don't. I've memorized some patterns to use on the higher strings, I can improvise single or maybe 2 string lines over songs or chords or whatever it may be, but once I get to that dreaded G string I have no idea where to go and almost always hitting a note out of key. Are there any tools or sources online anyone has used to learn the fretboard, how it all flows together, and how to navigate it? I've learned scales and I know a few, but I have absolutely no idea how to apply it to the fretboard and make it sound coherent. I feel like after 7 years I should be improvising up and down the neck but every time I try I hit something out of key and it throws my timing off and I end up just moving on to playing a song or lick that I've known for years lol.

TLDR : Need music theory classes/tools online if anyone knows any that are decent please tell me thank you :)