I am fucking losing it

My probably best friend found lots of new friends and thats good for him but im a jealous person, so when they do stuff without me i overthink it ALOT, idk if he even cares about me and ik i sound soooo dramatic but he barely talks to me when his other friends are around, they plan stuff without me, etc etc. Im also a sensitive person and lately hes just been kinda rude yk? Im definetly overthinking it but im just so scared of losing him, and i feel like such a side character, im nobody's best friend, im the guy at the far corner of the photos. His new friends r rlly cool and theyve become my friends too, but in the span of not even 2 days theyve become so close, mabye even closer than i am with him. I cant help but feel boring or lame compared to them, mabye he doesnt even like me, my ex said i was too much and mabye she was right. Idk if he even cares about me, i mean he tolerates me to some degree and he invites me to stuff but it feels like hes just ditching me for them. I have sewerslide plans and i just wanna do it now because it really feels like almost nobody cares abt me, but there are things i have to do first so i need to wait.

Thanks for listening to my narcisisstic ass vent, byeee!!