Feeling crazy//think It’s aniexty

I’ll be at school and a lot of the time I sit there and feel like nothing isn’t real or I’m having a dream and I can almost feel my head being triggered and my limbs tightening up.

It feels like I’m not in real life I feel crazy and it throws me into panic attacks it especially happens in cars or outside for some reason..

Please give advice if you’ve experienced these is it mental illness?