My husband playing around with slut...

This is my 2nd mariage, the 1st mariage I divorce bcoz he cheating on me and I hv 1 doughter from him. I divorce when my doughter still baby.since divorce, my doughter never meet her dad. Than 5 years letter i decided to get mariage again. I'm 100% trust him as he knew the reason why i divorce. Day by day i move on from 1st mariage and im so happy with my 2nd mariage. but than now nearly 1 year our marriage, i catch him playing around with slut at home. Me and my doughter went to festivals in city. He was rang me about 3 o'clock in the afternoon. He asking what r u doing? What time u'll be at home? I said to him that i'll be at home before 9. After he hang up the phone, i feel like wanna go home. So at 5pm O'clock i decided to going home and i rang my husband that I'll be at home around 7pm. Sounds like surprise when he said "what???" And he said can u wait dont come home yet bcoz i want u pic up some stuff from my brother? But he didnt pick up the phone, can u wait until i ring u back what tine he'll be at home. And I said im on free ways now, its in the middle between go home or go to ur brother place. He said just wait I'll call u back. After 30 min in waiting on the side of emergency call on free ways I decided to going home without tell him. Than i reach home,i cant open the lock door from outside bcoz he hanging the key from inside. As usually he fall asleep, I dont wanna wake him up or call him to open the door, i decided just go to back yard and open the gate. I was shock seen lady hiding and sitting down beside my husband ute.and I said to her come in side the house or i will call police. When i go inside  the house from back house door,the house is full of mess and tissue are everywhere. Sudenly my husbang come out from the room and screaming "whose that lady" and I said this lady is in the backyard and hiding, who else if u not let her in? Than we are argue. Worst become wors. I lost my trust but I  do still hv love. Feeling wanna leave him but I  feel I cant live without him. Its stressing me and I  dont know what to do. My doughter love him very much, she dont know that he is not a blood father. If i leave wich mean i take her happiness wich just got in 1 year. When i said to her this is your dad. I can see its meaning alot for her. Now what im gonna do.. i cant forgive him as he knows i hated cheating. Im so sad and im thingking of my doughter too..