Hi K.,
It sounds as though you have spent a great deal of time with your son but now he has come to depend on you for his entertainment and you have other interests like working on the house.
This transition will not be easy. You are the only playmate he knows.
You may want to try having him go to his room or a different area in the house within earshot but away from you for some "quiet time" to make a 'surprise' for you.
Tell him you want him to draw a very special story, to take his time and put all the characters in it. Then he can tell you about it. Be sure he has crayons and paper. When he returns in 60 seconds, tell him to add more detail but compliment the work. Stretch the time as long as you can without frustrating him. This way you are not pushing him away so you can do a project, but encouraging his creativity and still getting the time you need.
I provided a record player,( YEARS ago) childrens records and toys in his room, and insisted on quiet time a few times during the day for about 15 minutes leading up to 1/2 hour intervals, explaining that we BOTH needed some quiet time. Little by little he found things to do,play with his GI Joes, sang with the records, looked at books, did puzzles. Eventually he took his own quiet time.
I'm wondering why you have not considered pre school, perhaps two or three days a week for socialization with other children?
I think it is healthy for children and parents to have space. Wishing you well.
Justine