AIO; going through pregnancy and postpartum completely alone

Am I overreacting for being upset that my fiancé abandoned me while I was pregnant?

I’m really struggling with guilt and I need outside perspective.

Last summer I got pregnant. During my pregnancy, very early on, my fiancé left me — for another woman (his ex gf he shared 2 kids with, they had been split up for 3 years, so I was quite literally completely blindsided by this). He moved away and has been avoiding any responsibility for the baby since. Before he left, he ultimately ended up telling me that we would figure out stuff to do with the baby once she was born. She is now 6 weeks old and he missed her birth, hasn’t met her, and is avoiding all responsibility. He blocked me halfway through the pregnancy.

Since then, I’ve had to go through pregnancy mostly alone, pay for all the baby-related expenses myself, and now I’m taking care of our baby on my own. I’m also dealing with postpartum recovery without a partner, which has been really hard physically and emotionally.

I also want to say he makes well over 6 figures and has an extremely successful career and life. He was never abusive or bad to me in any way. This is something I truly never expected from him. From the outside looking in, he seems like a good normal human.

Recently, I’ve been taking legal steps to hold him accountable and help with support, but the whole situation has been stressful and honestly heartbreaking.

Here’s where I’m conflicted: sometimes I feel angry and hurt that he abandoned us, but other times I feel guilty… like I chose to keep the baby and take this on, so maybe I “signed up” for this hardship and don’t have a right to be upset.

Am I overreacting for feeling this way? Or is it valid to still expect him to have stepped up, even if I chose to continue the pregnancy? I spent my pregnancy trying to heal from this and move past him, I can honestly say I have no romantic feelings for him anymore, however my heart breaks for my daughter.