Following my previous question, today and yesterday the feeling of disconnection and as if I'm in a dream is getting worse. Is this serious?

In a dream? Not sure what the original question was or the exact symptoms, but actual diagnoses of derealization or depersonalization are uncommon. We need a more accurate history taking and assessment of present symptoms in order to diagnose correctly and provide the best treatment. If you have some type of thought disorder it is extremely important to see an experienced psychiatrist for effective medication.
See a doctor. This is called depersonalization or derealization and may occur with severe anxiety, under stress after witnessing a trauma or enduring abuse or violence, and with medical conditions such as seizures, head injuries or being under the influence of drugs or illicit substances. You can see a physician for evaluation and a workup for medical and/or emotional causes.