Step parent loss

Sorry for the long one here. I am New here and unsure how this works so sharing my story/ current experience. I am also Unsure if this “qualifies” under parent loss. I Grew up from 6 or 7 to 34 with step dad and was really close growing up, and even later on, an my kids were there more than they were at home because the kids and my step dad loved it that way. I was often there, especially after I had my kids. We were there so frequently and so close he would ask where we were if I wasn’t there with them. I also helped out with appointments after he got sick or would just go with them and near the end also spend a lot of time helping him when my mom was unavailable or had to work. His two boys and myself never were as they were 5-8 years older than me. My mom never got married to him despite him asking her to because his son from previous relationship didn’t want him to (his own words). My mom and I Moved into his home when I was in 1st grade and lived there for significant portion of my life. His kids were rarely around, especially when he needed them, unless they needed something and one always treated him like poorly when he was around. They rarely went to family gatherings at step dad’s family’s especially as adults. 5 years ago he got sick with cancer which ultimately caused his death in June last year. They suddenly started being around slightly more but not by much, but would make a big deal around “ family” and “ support” however still only when convenient for them, often not when he needed it. Near the end they made him go to a lawyer to write a trust and made my mom sign her name off the house to put it in a trust with the three of them. I don’t care that I got nothing as that isn’t important to me However I won’t lie that it hurt to not even be able to know what was happening with things to be a support for my mom and step dad through all of it. They would invite us all over for more gatherings here and there in the last 6 months to a year outside of the only their kids birthday’s. But even during these my stepdad was often siting with my mom and I and his kids would more interact with everyone else. They only seem to be around at the very end in the last 3 or so days as he was passing. I spoke at his funeral and only hoped that I too could remember him as my dad ( not just step) on the stone however was told absolutely not because “ I have my own dad”, not even “ step father” . I understand people grieve different but this stung bad, though I was able to speak at his funeral. Before hand they both said neither could afford to keep the place after his death so my family was talking about us buying it to keep in the family since all the kids grew up there and they had voice no issue with this and even seemed to agree . After he passed however the stepbrothers started continually harassing my mom about money that both my mom and stepdad s name was on, only speaking about money to her, or if bills got paid. Then began selling everything including the couple of things step dad wanted to stay at house for my mom to use if/when needed and he had wanted her to be able to stay there for rest of her life. Then they began to meet secretly about the house and trust. I had set her up with a consult with a layer with all the things ( to many to list) they had been putting her through so she could know her rights and not be taken advantage of and after it was scheduled and before meeting with him they decided to come for another “meeting” and told her they were buying it and had been in works door some time, “ over their dead body” would my family buy it, they only put up with us for gatherings, and that they were essentially kicking my mom out since they were buying it(they knew my mom couldn’t afford to buy it) and we’re only giving her essentially 2-3 months to move out of the home she had lived in for almost 30 years. Longer than either of them had even lived there. Now I have been helping her to move and today we emptied the room I had during my time there and seen it empty for the first time since I had moved in when he had to empty it for me. It hit a lot harder than I expected and I know once her things are completely out and we are done it’s going to hit even harder knowing that I’ll never get to return to the place I will always consider home, that I grew up in, lost pets at, my kids have basically grown up there, and even got married there and lost step dad there, and that those I had considered family and thought they did too ( though not close ) is also not only gone but apparently was never true. They have also started trying to turn other part of step dads family against us and despite not having gone prior are “ not going because of her” to their holiday gatherings. They have accused her of many things that they are actually doing to her, not her to them. I am unsure how to process it and feel like I “ don’t get to” feel this way because he wasn’t my bio dad especially with how they have been treating me ( and my mom). I’m trying to also be supportive and strong for my kids as well as my mom through all of this and neither of us seem to even get to grieve, especially her who has also basically been his full time caregiver for the last year or two and been the one to be there for him before that with any of the tough times that he went through, including the 5 yr illness.