How can someone be so narcissistic?

i raised my 2 stepchildren, now w/families of their own. their birth mother moved here when the daughter became pregnant. she said her daughter needed her. this was my little corner of the world. we moved here to get away from her always being in our business, sniffing for a dollar. she's a con artist, manipulator with attention craving disorder. the 'ex' iz on her 5th marriage now, claiming abuse again. she brought all this up on mother's day. 2 years ago when I flew the kids and their dad to attend a family funeral, she called the kids threatening suicide. she convinced the daughter to 'borrow' money from me. she has wrecked 5 cars & never charged w/ a DUI. the kids locked her up in rehab. she got out and posted to FB "thanks for the relaxing week at the spa." so, i feel resentful. i raised these kids. i sacrificed my life. i don't have my own kids. she came back in our life and pushed me aside because she is Here now the kids didn't even call me for mother's day. this hurt my feelings. i raised 2 others kids who's mother also dropped their kids off after they "had to get their life together". those 2 acknowledged me and filled my heart. i do the right thing and i just feel like i get the shaft. my stepson told me he would do anything for her cause she is family !! the 4th ex husband and i are friends, cause he is the only one who doesn't call me paranoid and crazy. i just feel like i wasted the last 25 years of my life !! also, at my step-daughter in law's baby shower, she kept telling everybody stories about the father very loudly. even though she only spent 7 years w/ him. at family functions, i hate to go. she walks up to me and says "thanks for coming" like She is the hostess !! why is this bothering me and hurting me so much ?