Im sorry if this is long I feel like a bad person

A few days ago my sisters boyfriend is coming over and I was jealous because I feel like my boyfriend is supposed to be only guy that can come over I know it sounds toxic but whatever ( my sister moved in with us to get her life together and she got a new boyfriend) . She asked me to ask my boyfriend if he wants to come with us to the mall and I was happy and I imagined us on like a double date but sadly he worked. The day we were gonna meet my sisters boyfriend and I was getting ready because we were going to the mall and I did my hair and I felt pretty . And then I’m like am I being pretty for him? When my sister’s boyfriend actually came over, I saw him through the window and noticed his arms, which reminded me of Erick. I felt shocked, happy, and sad at the same time. Then I saw my mom talking to him and laughed because the way he nodded reminded me of my boyfriend . My mom asked me how my boyfriend was, and for a second my brain almost connected my boyfriend with my sister’s boyfriend, then I caught myself and remembered that my boyfriend was at work. I also felt like I didn’t care for my boyfriend was at work, but then I pouted and wondered if I was just acting. Then we went to the mall and my mom wanted me to get her water and I didn’t really want to go because it was awkward and I was shy . Then I saw the guy and I asked for water and he looked at me and it’s like “ oh he looked at me so he must think I’m pretty” and I stoped it and I’m like TF And I felt weird like why did I feel that? I remember being awkward around my sister’s boyfriend, but I don’t remember actually having a mini crush on him. However, when I replay the situation now, my brain makes it seem like I was being shy, cute, smiley, and excited to see him, almost like I was single. It feels really real when I replay it, even though I don’t remember feeling that way in the actual moment My brain has also started bringing up old memories from when I was younger where I might have wanted a guy’s attention. I don’t understand why those memories are suddenly appearing now, and then my brain uses them to make the current situation seem like a pattern. Today, while doing dishes, I randomly thought, “Do I really want to experience new love?” My brain immediately started creating images/scenarios around that thought, and they felt very real. Then I remembered my boyfriend and got a heavy feeling in my chest and felt really sad. I started wondering if I was scared or if the sadness meant something else. Overall, I feel like my brain is taking random interactions, old memories, daydreams, thoughts, and feelings and turning them into evidence that I have feelings for other guys or that something has changed with my feelings for my boyfriend . I keep comparing feelings and replaying memories to figure out what is “real.”