Dating a Dad /Blended family - I Need Emotional Support

Kate

I am 22 and he is 29.

We spent the last 6mo of 2018 living with grandma and his 2kids , 9 yo son and 5 yo daughter. Daughter likes me more than son but I accept he is older.

Kids generally accept me . . .

Bio mom is not in picture. She is banned/deported +10 yrs from the US due to criminal record .

My trouble:

Constant bio jealousy ... Although im lucky their mom isnt in their present life, she barely calls her kids.

Bf is still married to ex wife legally but claims separation ... I get jealous and have horrible reactions every time she is brought up but it is my distrust that he keeps hiding things from me... Even tho it is not true...

And every time I look up stepparenting or stepmom articles and help I want to cry.

I think it might be grief for the "first family" feeling bc i never wanted kids until this relationship and I had 2 abortions (of my own choice) bc living with bfs mother she was abusive to my bf growing up and makes questionable life and parenting decisions , and i did not want her near MY potential child whatsoever....

Plus I am waiting to get married but I feel like im waiting forever for his divorce proceedings and it is making me want to break up.

As much as my partner has tried to assuage these feelings of anxiety I still feel like Im not doing anything right...

First 6mo living with them were transition period ofc and that was the hardest as i argued with him and his mother about the kids but learned to

Disengage and let the parenting be their father...

But now we are back in homestate away from his mother, the 2 kids are moving back in with only us...

I am scared out of my mind. I barely got out alive living with his mother but I had no family or friends around.

Now i will have family and friends around,

But

I am still thinking of breaking up because I feel like im overwhelmed ...

We've been together almost 3yrs.

I dont want to break up but stepmomming is exhausting emotionally but i will scar these kids and my bf if i leave the relationship...

My heart says stay but my mind says move on, its more pain than its worth.

But it takes time to blend a family even years.

What do I do?