I'm lost...

I'm almost 19 weeks pregnant and my SO and I have a very boring relationship. He views spending time together as sitting on the couch while we watch TV or he plays games on his phone. We hardly talk to eachother. When we do talk to its pretty much because we're fighting about something and the other day I found out he's been lying to me for what I think has been a long time. When I confronted him about he completely denied it and continues to denies it still even though the proof makes it impossible. I don't know what to do. I feel like even if I were to except it and get over it our relationship will never be the same knowing he doesn't have the balls to come clean. I think he's doing it because we have a baby coming and doesn't want to pay child support and his parents will be very upset if we don't end up getting married. Am I just being selfish? I just don't think it's a good enough reason to stay. I deserve to be happy too right?