Weeks of feeling numb and apathetic then sudden periods of strong anxiety and anger. Does anyone else switch between feeling nothing and feeling everything?

I think I have mild depersonalisation as well as depression and anxiety. I can go weeks feeling nothing at all as if I'm not even real and then I'll suddenly switch into a very anxious, angry and tearful state. It's almost as if I'm switching between depression and anxiety. I have constant symptoms of fatigue and negative thinking but I don't always feel this emotional. I just had a panic attack after several weeks of feeling calm and empty of emotion. This is what triggered me to write this post.

Anyone else relate? It's difficult to know if I'm getting better because how I feel changed so drastically.