Was this assault?

so basically this thing happened in january or this year. I had been talking to this boy for a few weeks and we were out together and he said he wanted to run by his house to grab something so I said okay. we went to his house so he could “get his wallet” and I was afraid but his mom was there so I didn’t think t was a big deal. his mom suddenly left and I was terrified. like frozen. he was kissing me and I told him I didn’t want to have sex but he didn’t really listen that much and he jsut keep feeling me up and trying to kiss me and I just kept pulling away and turning away and putting my head in my hands and I jsut kept saying oh my god oh my god because he wouldn’t let me go and he kept telling me to calm down and that I shouldn’t be scared and he jsut kept touching me and I couldn’t breathe like I felt like he was crushing me. afterwards I went home and stopped talking to him. ever since then i’ve been having nightmares about being raped, I look for his car everywhere and I won’t go into a store if I see a car that’s the same as his in the parking lot. I can’t sleep without my light on and I’m not motivated to do anything or go out anymore because i’m constantly on edge. I had a panic attack in the movie theatre because the man sitting next to me looked like him. I just feel numb and empty and like he took everything. even though It’s affecting me so greatly I still doubt myself. I still think i’m being overdramatic or that it was my fault. I haven’t told anyone about it especially not my family because when my sister was raped they acted so supportive but behind her back they accused her of faking it for attention. I truly think of they did that with me I wouldn’t be able to handle it. I think it would send me over the edge. I guess i’m just looking for reassurance that i’m not just making it up in my head and that my assault was real and my feelings about it are valid since I can’t get it from anyone else. i’m only 15 and I feel like my life is over. like i’ll never move on from this.