I feel for you so much as you face such a mind altering and sometimes seriously scary experience. While our sense of reality is what grounds us, no one really talks about when things begin to feel completely unreal.
I'm going back quite a number of years when I speak of my own derealisation experience, which tells you that this is well behind me now. This period of time became very scary for me, especially when I found no one could help me make sense of it. It got to the point where I recall one night crying out loud 'I just can't do this anymore!' It had become mentally exhausting and felt truly torturous. I too felt like I was going insane. Eventually, I found my way out of it with the help of some solid advice - Ground yourself in as many ways as possible, almost to the point where life becomes mundane. Looking back, I now realise that during this grounding process, I was focusing on the mundane as opposed to focusing on 'what seemed real and what didn't'. I wasn't so much in my head, trying to decipher my thoughts all the time.
It wasn't until some months later that I came across an article about something called 'Kundalini Awakening', also know as 'Spiritual Awakening', 'Spiritual Emergence' or 'Spiritual Emergency'. I couldn't believe it, I ticked just about every mind altering and body altering symptom on the list. When I say 'body altering' what I mean is symptoms including physical hyperactivity, states of sudden exhaustion and so on. So, from there I began focusing on aspects of spiritual emergence, which is what has led me to where I am today. This journey began more than 15 years ago.
I know anything that has the word 'spirit' or 'spiritual' in it can be incredibly off putting for some and I understand that, I really do. I've come to realise over the years the benefits of looking at things from 3 perspectives - Mind, body and spirit. Another way to phrase this is Psychological, biological and natural. Actually, there's a book I love written by Dr Joe Dispenza called 'Becoming Supernatural' where he takes Mind/Body/Spirit and translates it into Neuroplasticity/Epigenetics/Quantum Physics.
It's seriously tough when you're trying to figure out which reality is real. It can definitely feel torturous without some solid guidance. Of course, mine is only one perspective. I hope others can offer you their experiences and ways they managed.
I should add that once I became grounded, from there life ceased being mundane. Quite the opposite.