I’m struggling to deal with motherhood

TLDR
I can’t keep lying to myself and this is the only place I feel like I can post but this mama is struggling. For those of you who don’t know me I’m a first time momma to twin darling boys who have just turned 2 over the summer, engaged to the most amazing man and reconnected with my blood family and have built and amazing bond with my cousin and my fiancees family. Unfortunately I’m struggling with the depression, the parenting, the letting my babies grow, setting healthy boundaries with my family and so much more. I don’t know who I am anymore and it honestly terrifies me. I’ve always been told that I’m sweet and kind and an amazing mom so why do I struggle to accept those compliments? My ‘oldest’ has been struggling with sensory overload the past few weeks and today’s major blow up led to an hour long cry session over brother kissing his cheek. We have appointments set to check if he has any development issues coming up next month, and it terrifies me if I get the news that he’s autistic or in that ball park. I love my sons to death but my brother is on the spectrum and my dad is a complete piece of shit with soooooo many psychological issues. My full siblings and I were adopted at a young age and I just connected with them in May, so it’s been super overwhelming researching my gene pool. I wasn’t prepared for my pregnancy so all of this is still new to me. I’m so lost and feel alone.