boyfriend has 4 kids already & IM JEALOUS

I hate that I am so jealous of my boyfriend babymomma because she gave him his first child within weeks of trying and I have been trying for months nothing. When he talks to his kids with so much love and passion , I get sick to my stomach because I want him to talk to our baby like that! He always comfort me about being jealous and say it will happen but im sicka hearing that! I want a baby!!! I have a son but not with him. God I wish it was. Am I wrong for being jealous of the kids ? I just want us to share a baby so bad! When I F I N A L L Y get a good man and not a deadbeat like the first im struggling to give him the one thing we both want! UGHHHH