AM I CONFUSED OR STUPID?!!!!

Am in a relationship with someone i love so much. He cheated on me with some girl and i was able to find out. When i asked him, he accepted his mistakes and asked for forgiveness. But my problem is, he's still seeing this girl and he tells me everything that is going on between before and after they see. He needed me to give him sometime to end the relationship with her because he believes she's a small girl. I believe he loves me too. Please what should i do???