Riddled and eaten alive with guilt. But wont he resent me

So the story is. I was seeing a guy for a few months who was living with a girl he 'apparently' dosnt love. But is there to support his two young sons until there older. One is 4 one is 2. (Yes i know im such a horrible person for that and thats what i have to live with no one else, im not looking judgement as he did lead me on in alot of ways also) but anyways. He was soooooo adamint on never having no more children. He ALWAYS spoke about how he wishes he never had kids etc. And deff not yet (which personally i find horrible because they are here now) but this girl trapped him and they werent together very long when she concieved his first son. How he was for walking away and doubted the child was his etc but his mum told him to do the right thing by his son and stick around until he was old enough to know him and that. And then as soon as his first was born and they slept together she was preg again. And so hes there for them two boys but there getting older and know him well so hes considering leaving at some point bla bla bla. But anyways. In his eyes. It was all her fault. Apparently. And hes too good for her he says. And she has trapped him. So he ALWAYS everytime we where together spoke of never having more kids. This was something that really ment alot to him. He never shut up about it. Said he didnt want children to two diff women and all that aswell. So here i am. Sitting 6 months pregnant with his daughter. And havent told him. And i can lie to myself that hes this and hes that and dosnt deserve to know etc. But im not fooling myself. I know deep down the only reason i havent told him is because i am so terrified to ruin his life as it is now. And what he has. Im terrified to hurt that girl hes with. Im terrified to hurt his sons. Im terrified to ruin lives. Im terrified he will resent me and hate me. And that i will get all the backlash from him. I dont want him thinking of me what hes so eagerly telling people about her. Oh i trapped him. I set out to ruin him. As it seems in his eyes to all be the womens fault. But he isnt a bad father. He has done the right thing he has stayed in a place he dosnt want to be and is unhappy. To spare the happiness of his sons ans see that they have what they need. Alot of men cant even do that. My sons dad was with me years and couldnt even stick around when i had him. As much as hes an unsavoury character hes became mature enough where responsibilities lie. And the only person who looses out on me not telling him is going to be my daughter. Wont she hate me for never telling him she exists. Wont it all come out one day anyway everything does. Wont it just be worse then than now. What is the right thing to do. And how do i even tell him. Ive never been so terrified of something in my life. But i cant carry this guilt around anymore that im not doing whats right!!