You say what you are feeling now is completely different but I strongly believe it's the same derealization, brain fog, Depression but just more severe. You are very likely not in a suitable state of mind to decipher what is really going on.
I agree with your friend that this is a sign of and how I believe schizophrenia often develops. That is not to say you are even close to that point yet but it develops over time.
Your conscious mind and subconscious mind feed off each other if you allow it. Your initial reaction was subconscious but it has escalated because consciously your're feeding into it. It doesn't even necessarily have to be a decision, but just a reaction. Like by not separating yourself from it consciously you are escalating it by default.
During times like this, you need to be relentless with your self awareness, constantly checking on yourself. Behaviors, like aimlessly wandering the streets, being completely out of your control is an illusion. Thinking you need your friends there to protect you is an illusion. Your conscious mind through constant self awareness is your stability that prevents you from getting sucked into the vortex of negative symptoms. You have to separate yourself from this activity and just watch it like you are watching a child throw a temper tantrum. Don't react.
This will likely blow over on its own at some point anyway but it will take much longer than it needs to and more importantly, you want to train yourself to be in control during these periods.