Ending a relationship is never easy, what you will want to do is sit down and have a conversation with him. Let him know that even though he wants to stay with you the reality is you think you need a break. Explain to him that if he is not willing to allow you a break then you will have no choice but to end the relationship completely. The key is getting him to leave........then once he is gone if you want to keep it apart then you can tell him this.
Explain to him that this is your home, and you would like him to leave. Explain to him you want to keep this peaceful in case you can work out the problems but if he is unwilling to work with you then how are you ever going to have a chance at reconciliation if you change your mind.
Remember to keep calm, and simply tell him you need some space. Do not emphasis on the breaking up so much as just a break. If he believes that by leaving you will have time to think about it then it will be easier when he is out of the house and everything calms down.