My grandma is driving me crazy..?

ok so i'm 14 and live with my parents, aunt, and grandma. my parents and aunt are fine, but my grandma >.> well to start she's super nosy. she has to know where we all are at all times. and then she only calls you if she wants you to buy something. i know those things are irrelevant, but here are the things that really piss me off... she is a hoarder. we have boxes everywhere. our entire back porch is piled to the awning with her crap. we have two small rooms completely filled with her stuff. then our ENTIRE 3 car garage is filled with her stuff. then she also has 2 public storage sheds. we tell her to get rid of it and this is what she says "its valuable or it gives me memories or the person will be mad if i throw it away." the second thing is she just likes to put me on guilt trips. in november her mom died. and in like june i think, she was gonna visit her (she did weekly) and i told her in advance that i couldn't make it. and she said that was ok. the day before she was leaving, i was going camping. apparently she forgot that i wasn't going. so i'm just standing there while she's yelling at me saying things like "Its your fault she is going to die," and i said that i would call her weekly. so she replies oh im never going to let you talk to her again and your not allowed to come to her funeral. WTF!! so then today, i accused her of eating my food i specifically told her not to, so now she's saying that its my fault that she's about to have a nervous breakdown and that im a spoiled rotten brat, and an a**hole. she always says that to me and things like i'm going to end up with no friend (not to sound vain but i have a lot of friends) and that i'm not normal and that i scare her. while everyone else in my family thinks i'm just fine and she drives them crazy too. and another thing that gets me REALLY mad is that she's always telling my mom how horrible of a parent she is because she isn't raising me the way that my grandma would want.. so yeah we just fight all the time and i just am ready to just GAH -.- what should i do?? like should i just ignore her or what. i'm starting to get so angry i wanna scream just evil little comments at her but i'm above that, unlike her. it sure feels good to vent lol.