The huge number of deaths caused by the novel pandemic COVID-19, which can affect anyone of any sex, age and socio-demographic status in the world, presents a serious threat for humanity and society. At this point, there are two types of citizens, those oblivious of this contagious disaster's danger that could be one of the causes of its spread, and those who show erratic or even turbulent behavior since fear and anxiety invades our surroundings because of confinement and panic of being affected.In this paper we aim at developing a smart ubiquitous chatbot, called COVID-Chatbot, for COVID-19 assistance during and after quarantine that communicates with a citizen to increase his/her consciousness towards the real danger of this outbreak. Furthermore, COVID-Chatbot is able to recognize and manage stress, during and after lockdown and quarantine period, using natural language processing (NLP).The robust messages delivered from COVID-Chatbot and its way of communication could possibly help to slow the COVID-19 spread.The proposed method is a ubiquitous healthcare service that is presented by its four interdependent modules: Information Understanding Module (IUM) in which the NLP is done, Data Collector Module (DCM) that collect user's non-confidential information to be used later by the Action Generator Module (AGM) that generates the chatbots answers which are managed through its three sub-modules. And finally the Depression Detector Model (DDM) that detects anxiety in the text input through a deep leaning sentiment analysis model to help AGM make the decision to deliver a reassurance message if a bad behavior is distinguished.