It is good to have a question from a father; most come from mothers.
You did not say how long ago this behavior appeared or what was going on in your family at that time. Nor did you indicate whether the things that concern you came on all at once in a big package, or whether they crept up on you until you became aware of the change.
Regardless of the pattern that describes your son’s behavior, it is obvious he has developed a high degree of anxiety. It sounds as though he’s fearful of losing you and wants to stay around you all the time. I think he needs a lot of love, reassurance and togetherness right now. Don’t remind him of what a big boy he used to be. Just arrange to be near or with him and say something reassuring like, “Isn’t it nice that we’re all here together.”
You mentioned that you had moved recently. Moves are often disturbing to children, and I would guess that it had something to do with the onset of this behavior. If your move was from a place in the same city, ask him if he would like to go back and see his old house. And try to get him to talk about his feelings at the time of the move and when you moved into the new house or apartment. If you’re patient and understanding, I predict his behavior will gradually change back to his old pattern.
Our parenting advice is given as suggestions only. We recommend you also consult your healthcare provider, and urge you to contact them immediately if your question is urgent or about a medical condition.