Seeking advice. Long post ahead...

Mga mommies, I just want to seek opinion regarding my situation. I met my now live-in-partner on our previous job at a restaurant last year 2019. The time I met him, I was a single mother with a 5 year old daughter, and he also was a single dad, with an almost 1 year old daughter. He courted me and after making sure that there really was nothing going on between him and the mother of his child, I said yes and we're in a relationship up until now. My situation is that the mother of his child is umaasa pala sa kanya. My partner has made it clear to me that na wala talagang sila, may nangyari lang daw sa kanila twice and nakabuo and while the woman was pregnant, both sides of the family already made an agreement that the focus is the child, even his family told me that as well as our common friends who knew the woman. Then on our first few months, I am suddenly hearing and my partner is telling me that the mother of his child is nagpaparinig sa facebook na aalis na sila ng place nila and uuwi na ng probinsya without him knowing and there has been lots of posts on Facebook na nagpaparinig na aping api ang mother and parang iniwan, na pinangakuan siya ng ganito ganyan. I asked my partner about it and he said he doesn't know as well because ang pangako nya lang is for the child. From then on when the girl knew we were together, he treated my partner ng mas hindi maganda and eventually threatened that she'll have his surname taken off the child. I told my partner that he needed to confront her and wag iuna ang init ng ulo because he was extremely frustrated with the girl that it affected his visiting with the child. I told him to understand her, because it looks like the girl was expecting that once they had a child, there was a possibility of them officially becoming together, unfortunately, as it saddens me as well, that doesn't how it worked out with them. Then my partner had problems securing a job starting the Taal eruption then came the lockdowns so he wasn't able to give help as much as he can so it was also a factor that the girl is using against him. Up until now, he still haven't seen his child or making efforts to do so yet, because of the pandemic, he's still jobless. And also, I'm currently pregnant with his child. I'm on my 5th month of pregnancy now, we're extremely happy with our blessing. It's just that I've been feeling down because I feel really bad for his child, I was a single mother too and I know how it felt though the response with being a single parent is completely different from how the woman of his first child acted. My hubby plans to secure a job first so that may mahaharap na siya sa family and maging consistent sa bata though it has been really hard since the pandemic. My question is should I be involved once he and the woman talk? How should I feel about this situation? I feel guilty because I feel like I'm tolerating his actions of completely ignoring or not even making "kamusta" to the family, though I understand how he's feeling towards the family of the girl and the possibility that he will rejected but I know that it really is part of him trying to reach out to his daughter, nanghihinayang ako sa oras na lumilipas na hindi siya nagrereach out sa family, alam ko ang feeling ng ganun dahil ganun din ako dati sa tatay ng anak ko however siya yung hindi naglaan ng oras sa anak namin kahit anong pakiusap ko. I feel like I should be involved because we're now partners. I really have lots of questions on what should I do or how I should be acting on this situation but I'm just lost for words. I hope you can help me out. It's been stressing me for a bit. And I'm not supposed to be stressed because I'm on a high risk pregnancy due to 2 previous miscarriages 😢 I've been making sure I don't feel upset because I immediately feel the effect of stress due to my condition. Hope you can help me out mga mommies, pasensya na medyo mahaba. God bless and keep safe!