“A Course in Miracles” says: “I'm never upset for the reason I think.” I imagine that this is true here. Your mom buying a ticket for your cousin is not the real source of your hurt. Instead, it's the profound sadness that you feel for a lifetime of living with an emotionally absent mother. When you embrace that reality, you'll know longer react to each incident that arises but practice acceptance and, therefore, have peace.
When I was growing up with an emotionally absent mother (but not knowing it), I got jealous and hurt when she did nice things for other people or gave them compliments. Then, I would get down on myself for being so petty and insecure. It was only when I became a parent myself that I realized how her behavior was not like other moms and that it would make anyone in my shoes feel precarious. I realized that a strong foundation of love and belonging was never constructed during my childhood. Therefore, I felt that I could collapse at any minute...and I often did.
Reading Jasmin Lee Cori's “The Emotionally Absent Mother” can help you put your feelings into context and see that you're not alone. Once you understand your past and put it into perspective, it's a lot easier to move forward and get excited about your future. What your mom says and does will no longer have power and you can finally live like a mature adult, not a child under her control. You'll become motivated to do what Bishop T.D. Jakes recommends: “Step out of your history and into your destiny.”