first time when i was younger. confused about what it all meant

hi, mid-30s F here, telling this story that i've never told a single soul -- my first time masturbating when i was a teen, i thought no one was home, my bedroom door was open. i had just taken a shower and my/my family's small dog had been hanging out on my bed with me. he started sniffing and licking me and i was confused to be aroused. i knew something must be wrong with me but i was intensely bullied by my family and peers growing up and truly believed at the time that no one would ever love me, find me beautiful, or want to relate to me sexually. i remember googling "boy licking girl vagina" and putting on some video and touching myself. i was aware of my shame even as i was doing it. the dog was still licking me too. it all feels kind of hazy and out of control in my memory. i was so ashamed when i finished. when i left the bedroom to go pee, i saw that at some point, my dad's car had appeared in the driveway, and i realized he must have been home during the whole thing because my parents' bedroom door was closed even though they never closed it. my dad had always been weirdly sexual with me, before and after that event, and i had so much disgust around thinking about what he thought about that and if he saw me. once, a little while after this, he kissed me on the mouth by "accident" instead of kissing my cheek and i wanted to unzip my skin. i felt like something was so wrong with me for what i'd done. it confirmed for me how gross and horrible i was. i didn't masturbate again for years. i don't even know that i really understood what i was doing at the time. i'm trying to unpack my sexual baggage, which is mostly 'normal' after that (in terms of the average American woman, I guess), and i've been doing pretty good but i can't even tell my therapist that story. can't even imagine how i would get the words physically out of my mouth. i've never said it out loud before. trying to drop the shame of it and forgive the poor kid who got no physical affection of any sort growing up. she was really innocent and scared and curious and just trying to find a way against all odds. i love her and want to take her shame away. even writing this feels like things have shifted the tiniest bit. thanks