Why do i feel this way?

Well I am a pretty outgoing person. not really that shy but not a total extrovert. I feel really uncomfortable when people put me on the spot. and sometimes my indecisiveness makes me pick really regretful choices. like when i ask my dad for something he Always says no. so now i feel like what's the point if i really have a great chance. My aunt recently asked if i wanted to go to disneyland with her this saturday. she would buy the ticket. everyone knows that it's up to my dad's decision and everyone basically know that he will say no. he asks if i want to go. i cautiously say i don't really care. of course i really want to go. he decides that i don't want to go. he calls my aunt to confirm that i don't want to. she tells me on the phone that she knows that my dad doesn't want me to go. He tells my aunt why should i go if i won't really appreciate it. she says it's okay to me on the phone but i still decline. now i feel really sad. I'm 13. my dad won't even let me stay over my cousin's house. just because i'm a big "girl". last time i told my dad what i really wanted...well let's just say it didn't go well. plz me help understand this situation.