Help with implementing continuous collision detection

So mostly for fun I'm making a kinematic character controller that doesn't use a rigidbody. I'm currently trying to implement collision but have been struggling with it for a while. I want the controller to use continuous collision detection so I'm using mainly capsule casts to make that happen. Sliding along walls works great too, but when the character walks into a corner or a shrinking corridor it starts to become very unreliable. In theory it should be able to handle any situation with multiple walls and so on but in practice it only does so half the time. Here's my code, but it basically involves moving right up to any wall it encounters and then projecting it's remaining movement onto the wall, recursively calling itself if any other walls are encountered when it's sliding.

I'm wondering if anyone either wants to take a look at my code to see if I'm doing anything wrong, or point me to some resources for doing this, because I haven't been able to find anything.