fixated on my boyfriends ex and it’s destroying my health

I dont know why i get like this bc i am not one to be like this or even care. My boyfriend dated his ex for two months his senior year of highschool so why should I care right? I DONT KNOW!?!? She is absolutely stunning and its the person he lost his virginity to which like ughh idk hurts to hear. Its not

Like im scared of her taking him away from me or anything but idk I seriously dont know why it makes me so upset to look at her or to talk about her even though ive been with my boyfriend for a year now. He is my first ever boyfriend and I dont want this to mess anything up. i do have severe anxiety which makes mundane and null things like this much worse but i just dont know why I am like this or what to do bc “just ignoring it” or “not caring” isnt working. Any advice? Can anyone relate? need all the help I can get so I appreciate it ❤️ thank you