*hug* It's not a real one, but the intention is there all the same.

You are facing a lot of battles. There's a reason things are hard.

First, your ex will not be the same in 18 years as they are today. That's a fact. Neither will you. And your child will grow into an increasingly independent human. Let your child delight you. Laugh at their smiles. Giggle with your kid. Enjoy what you have. Your ex will not be able to manipulate a 6 month old. There is time for joy before the worries you mention could come to pass.

And don't feel guilty about the ambiguity. It's normal to feel ambiguous, especially in your situation. That's fine. Accept it. Embrace it. It will help you teach your child about ambiguity in the world.

Start making friends with your child now. When you want to isolate, talk to the baby, sing to them. You know how you want people to treat you now? With kindness and care? Show that to your child, even unborn. Practice what it is you are not receiving... We all need good parenting. Even as adults. Show your child what it is you wish you were receiving right now.

Do have a swim. Feel the water embrace you.

Channel the depression and emotions into art or your writing. And if you can't, breathe and experience a sense of comfort that you can breathe.

I don't know if there is support for expectant / new mothers, but look for it. And take everything anyone offers you. You deserve it.