As others have said, your scumbag ex has no say whatsoever on whether you keep your baby, a baby he planned with YOU!!! He was having unprotected sex with you with the intention of getting you pregnant, so he doesn't get a say or to demand that you have a termination!
It sounds like despite your awful situation, this is a baby that was very much wanted! If you want your baby then you can more than do this! You don't need the sperm donor! You have all the love that you need to get you through your pregnancy and to raise your babies. Don't let him leave you with regrets that will last a life time. I am a big believer in things happen for a reason, this little one could be the shining light that brings you and your daughter through this dark time. A positive in this negative period of your life!
Please get your family to help you pack up your things from his house, you are entitled to have your things and your daughters toys and clothing etc! If he was any sort of man, he wouldn't have thrown you out on the street! What a selfish, nasty excuse for a human being! You are the lucky one here! Pity his awful OW, she has a consolation prize! A nasty, cheating scum bag, who has affairs whilst trying for a baby with his partner! Then throws his pregnant partner and their toddler out on the street, so he can shack up with his morally corrupt OW! In fact they deserve each other! I hate saying this, but ask your g.p about possible sti tests, he is an awful person to put you through this!
You have a bright future ahead of you, you have your beautiful daughter who will never need to worry about you deciding 'you are not cut out for parenting'. You have your family, your dignity and your strength! Your little girl is lucky to have you as her Mummy! If you need time to be just with your daughter, then cancel Sunday! You have had a shock and you don't need to be apart from your little girl if you are not ready! They don't get to call the shots! Block him on your phone and social media and tell him you will discuss access over email only! When you have had a chance to process things, then you email with your terms! You are allowed to take time to think and process what has happened! Don't be agreeing to any contact arrangements until you are ready!!