so pissed off

I hope this goes here. I have a cousin that is 10 months younger than me. In my whole life i have NEVER mattered. Anything i do she has to out do me. My milestones have never been special because of her.
Well I got pregnant last year (obviously) i was 18 and had a month left of high school. I told all my family and my grandma (dad's mom) was pissed. THEN when i was like 7 or 8 months pregnant my cousin comes out to say she is pregnant. She was 17, and not even close to graduating. I had my son (the first BIOLOGICAL great-grand son in my whole family!!!) well my g-ma was semi happy.... well my cousin had her baby last week and now NO ONE even really cares about Kaden. I understand that her kid is new, but damn its not like Kaden fell off the face of the earth.
I get emails all about her kid not even asking me how kaden is. I'm so SICK and TIRED of her always trying to one-up me. i'm glad she is happy and healthy and all, but i could care less if i ever saw her or her son!!!!
Sorry i'm just so sick of it. I'm probably really wrong to feel like this, but it has been going on my WHOLE life and i just want a break from it.