I don't know what to do anymore

Me and my partner have been together for 4 years. We still don't live together as we are saving for a house. He's has 2 kids from 2 different relationships. 1 he sees. 1 he doesn't.

I didn't know this until I was already pregnant with our daughter who is nearly 3.

I'm just completely fed up of it all now. He hardly sees us as he works 24h/36h shifts at work. But when he does see us he always cuts it short to go and see his other kid. And more recently his son which he didn't tell me about for months. He always makes sure he sees his other kids but he doesn't see ours. We will go on dates or he comes when she's in bed.

I'm at my wits end of what to do.

He keeps saying he wants to get married and I do really love him.

But part of me wants to tell him to make a choice which I knows mean.

Please no bashing. I already feel terrible