boyfriends girl best friend

so my boyfriend of 1 year and 2 months has a girl best friend and it honestly makes me feel sad and jealous. they both consider each other as their best friends they became friends in june. i overthink a lot and my anxiety makes me feel worse about it too. i get jealous of the attention she gets a lot of the times and it sometimes makes me feel like she’s taking my place. he recently gave her a bracelet that she wears all the time and sometimes but rarely goes to her house after work since they work together. he’s going to go to her house on tuesday next week for her birthday along with other friends. i’ve told him how i feel and stuff and he always just tells me not to worry. but i’ve heard so many stories where the girl best friend becomes the girlfriend or something like that. i just hate always overthinking about everything and it stresses me out. i don’t even bring it up anymore cause i’m afraid he’ll get annoyed with me and break up with me. my friends would even tell me how she would constantly talk about him in class every day. i would even catch her staring at me and also staring at my boyfriend whenever we were together. whenever i’m with them they just act as friends he always treats her as like one of his other friends. but the way she woudl look at him and talk about him is weird. i just can’t help but think that there’s something going on even though it doesn’t entirely feel like it. i wish he would consider me as his best friend since we’re dating. :(