Don’t know what to do

Please no bashing... so I was with this guy for 3 years and he’s cheated on me basically our whole relationship and he lies to me all the time. We have been split up for 3 months and I’m talking to someone else. Now the ex still lives with me because he has nowhere else to go and I don’t want to hurt his feelings or upset him by telling him to get out because I still love him with every piece of my heart but I know we can’t be together (I feel like we would be better as friends) the ex still wants to work things out but I don’t want to.. how do I get over feeling guilty for wanting to be with someone else..