Hi @Ap2021 ,
I hope you don't mind me popping on to your thread as well- I have to say, reading your post felt so familiar to me. I'm also a parent in a blended family, and I can honestly say that I could have written this post almost word for word myself a year or so ago.
Everyone's story is different, but I will say that we do hear a lot from people struggling to navigate the complex dynamics of a blended family here. In my case, it was just myself and my daughter for the first 4 years of her life. So we were very much a famliy of two (though I have a very supportive extended family and friends)- when I met my now-husband, it was a huge step for me to even introduce her to someone new.
For us, transitioning to becoming a true blended family was something that took a really long time, and involved a lot of difficult conversations, some tears, a lot of misunderstandings, and it's something that's only really become a smoother journey in the last few years.
Like you, I found it really hard when there was conflict between my child and my partner- I would often want to step in and play the mediator, but that would then cause other problems!
It took me a long time to allow their relationship to unfold naturally, and two things helped us a lot. One was getting professional support from Relationships Australia. The second was trying to be really, really kind and compassionate- both to myself, and towards my partner and my child. Sometimes I do this well, sometimes I don't, but I think it's really valid to feel a lot of really mixed emotions around this stuff. Sometimes I was exhausted by the fighting, sometimes I would be exhausted by trying to come up with fun activities for us to to, but it's only now that things have improved that I can see that we also all needed a lot of time and patience to find our feet.
I'm also wondering if you know any other people in blended families? Sometimes it can really help to hear from other people in the same boat as you- I've learned a lot from other single parents along the way. If it would be helpful, I'd be happy to have a look at some groups that may be suitable for you, and we also have a single parents space on our forums 
I hope that sharing your story here has helped a bit, we're always here to chat, and it's a very non-judgmental, safe space to share what's going on for you and your family.
