I 17M feel sporadically distraught being in a relationship with my friend 17F

Hi, I’m 17M, and I’ve had feelings for my friend (17F) for many years. We were best friends for most of that time, and last Valentine’s Day I confessed to her. She said yes, we had a “talking stage,” but that ended pretty quickly. Things were awkward for a while, but eventually we started talking again. Now, my friendship with her feels very inconsistent. Some days she treats me like her best friend and says so herself, but other days it’s like I don’t exist. I’ve realized that my mood depends a lot on how she treats me last — if we had a good interaction, I feel happy and excited to see her again. If not, I’d rather avoid her just so I can be myself and not feel drained. I also struggle with jealousy. There’s another guy in my class who used to like her (and still talks to her a lot even though he has a girlfriend at another school). She complains about him being an asshole, yet she still calls out to him and interacts with him more than me. That stings, and I hate that it bothers me so much. I know it’s not her “fault” because she doesn’t owe me anything, and I’d probably be told that I’m overacting and insecure(which I’m not denying) that doesn’t really make it better. But after years of this cycle, I feel like my emotions have gotten more turbulent and destructive. I want to get this under control, but ignoring her isn’t really an option because her voice is distinct and I notice it instantly. Graduation is only a few months away. After that, should I just cut contact with her? Maybe block her? Any advice? What about what to do in the mean time?