I'm sorry that things seem to be continuing downward. I've been there. And it [censored]. I'm sorry that the hits will keep coming; I hope that you can continue to weather the storm.
1) you need to figure out how to stop yourself from dwelling on what she is doing or will do. Thinking about her future children is a cheeseless tunnel. All it is going is hurting you. How can you work to train your brain to stop that? I used a rubber band on my wrist. After a couple days, I didn't think about what my ex was up to. You can also try visualizing a stop sign when you start to go down that thought road. But however you do it, you must stop.
2) you have got to get out of the house. Not move out. Just get out for a few hours at a time. Go do something. Anything. Go to the gym. Take up a hobby. Go to a meetup. Read a book at a coffee shop. You have got to convince yourself that your life will be ok with or without her. I highly recommend doing something new, but for now, getting out and doing something is good enough.
You say you are lost and want direction. But you e gotten tons of advice and I'm not sure if you've taken that first step. What are you waiting for?