Do you think I am just being a baby?

ok so last week was my b-day. Every year it seems to be crappy. no one ever throws parties or does anything for me which makes me feel bad. I'm 25 and my younger sister is 15. i always go out of my way and throw her a b-day party. It might not be much but you know grilling out with family, The same thing with my mom. I always want them to feel special but i never get anything in return on my b-day. I hoped that this year would be better. I did get an occassional haapy b-day wishes. My mom gave me ten dollars but she made me fill like it was a bill she was having to pay. She said she would cook me a cake. I finally got that yesterday (week later) it would have been later on this week if i hadent said anything. My cousin did buy me a book for a dollar and invite me over to eat with her and her husband. I was really heut by my sister. yea she is only 15 and doesn't have a job. But my mom gave her money and i thought at least shed get me a card. Fainlly days later she brought me a small bracelet for a couple of bucks but that was only after i said something. But her b-day is next month and she expects me to take her to the beach. My aunt told me that the week before when she had invited me to dinner that it was my for my birthday but i didn't know at the time. I had washed and cleaned her kitchen after dinner. well to make a long story somewhat shorter it really had gotten me down. To the point just thinking about it brings me to tears. I didn't want much just all of my faimly together for my b-day and just eating hotdogs and chips would have be great. I was just about over all of this until my one of my cousins who lives out of town called. Her mom which was the aunt i just mentioned, has a birthday this weekend. So my cousin wants me to go pick out a cake and when she comes down she will pay for it. Them have everyone to come over and have a surprise b-day party for my aunt. Well i started to cry and thank god my phone died. she didnt know i was upset. But i just dont think i can go. it was somthing i had wanted and i dont think i can be around my family while they are celebrating her b-day and just last week it was like i didnt even have one. Am i thining too much into this. am i being a baby? should i just get over it and just go? I mean this happens every year all year long. I feel like i am just an obligation to everyone while i do everything for everyone else. :(