I hope this helps. I want to draw your attention to something you wrote:

"She ended up getting pregnant"

If you re-wrote that to: "I ended up impregnating her" would that help shift your perspective to the idea that you are responsible for the outcome of your actions?

I get the impression that it is all about 'love' to you, and that sex is strongly tied up with love. But what I am really seeing in what you wrote is infatuation and lust. First for one young woman, then for another.

I'm going to be utterly practical here for a moment. If your baby mom has no means to support herself, I urge you to facilitate her getting the education or training she needs for your baby's sake so that she can create a healthy life for herself and the baby when you are out of the picture. Sit down with her and work out a plan to do this. Work out visitation for when the baby arrives.

In the meantime, then, think long and hard before becoming more deeply involved in a young woman's life who has a child and an abusive boyfriend, particularly when you are so ready to abandon the young woman you impregnated because you are no longer in love with her. I really do mean the best for you and your baby mom and the baby.