Thanks for posting a query,
1. Are you using any recreational substance?, if so you should stop using that.
2. Sometimes this happens when one is preoccupied with other thoughts.
3. Sometimes it can be manifestation of any neurological condition like seizure disorder
4. This seems somewhat like depersonalization phenomenon.
Are you having difficulty in concetration?
Loss of interest in day to day activities?
Lack of energy..
Next Steps
You should consult a Psychiatrist or physician to rule out underlying onset of any psychiatric illnesses or neurological illness