hiya,
i can understand that you feel pushed out by him wanting to spend more time with his kids, but he cant spend 24/7 with them, there should still be room for him to have a relationship with you, if anything surely it will help, it cant be easy bonding with an estranged child at the best of times, if you love him so much maybe just give him another go, but step back slightly while he finds his feet with his kids, i mean there is no reason for you to totally break up is there???