What is the reason for mood swings between loving to socialize with people and isolating oneself from them?

What you are complaining of might be a physical illness that requires consulting doctors and undergoing examinations, or a psychological illness such as anxiety and depression. We advise you to frequently seek Allah's forgiveness (Istighfar) and remember Allah (Dhikr), especially the prescribed remembrances, to consult mental health specialists, and to associate with righteous believers, due to their positive influence on the soul.