He can't claim you because you did not live with him the entire year. I misunderstood you. He can still claim your and his daughter if the baby lived with both of you the entire time since the baby was born. He would indicate on his return that the baby lived with him the whole year which is the correct answer for a child born during the year.
How much income did you have? I thought it was less than $4050. Regardless of how much you made, you can file a return as single and would get a refund of any taxes withheld if your income was not more than $10,350. If you made more than $10,350, your are required to file a return.
The two of you can decide who is going to claim your baby. Either of you but not both can claim the child.
