I dont know how I should feel or what I should do PLEASE HELP?!!!!?

(LONG BUT COPE WITH ME) My grandma had been sick 4 sometime. Dr finally found out wat was wrong & had back surgery. My oldest aunt is the one who always took my grandma to the dr appointments. since I am currently unemployed (by choice). I have decided to go along with them to dr appointments. I was once a translator for drs & patients for after hr services. my aunt thought it would be a good idea if i started to come to all the appt. i didnt mind i like helping my grandma & anyone who needs translating. by the time of my gmas surgery they needed someone who spoke english&knew my gmas med hitory. all my aunts & uncles & my grandpa dont speak english. and my grandma is 82 & illiterate. so i said i can go in with her. i was with her for about 3 hrs translating, signing papers and explaining things to my gma. was with her in preop room.saw her go in the operating room. surgeon called me on cell to let me know how everything went when surgery was over etc. ive been following up with the drs. i am practically the only person who knows dr names and her rx info. there were some complications in my gmas surgery & in order to save her life they had to put in a IVC filter. i explained to my gma and she said its fine sweety sign...i did. everything was a success! I noticed my uncle the youngest of my gmas children started acting distant & stopped talking to me. today he came to my house being quiet and ok... then out of nowhere... he starts telling my aunt and my mom that they should have someone responsible making decisions for their mother! my mom got mad since im her daughter & was like no one is making decisions for mom she is. he said no! one of you guys should be taking care of her.... not someone who is going to change their mind and not be responsible. i said your talking about me and i dont make decisions for my grandma i explain things to her she decides 4 herself... he was like no you make decisions for her. tell her what she needs and what she has to do. it got heated up he started calling names & pointing fingers.i honestly only tell my grandma what the doctors tell her to do... which is to walk & not be laying down all the time because she needs the exercise.i tell her to eat because she doesn't really eat. i tell her to wear her back brace. etc. my gma doesnt want to she says shes too weak still ITS BEEN OVER A MONTH... she refuses to do any exercises complains about pains & doesnt want to leave the house without her wheelchair. BUT she tells my uncles & doctors she feels no pain at all that shes fine now & exercises & lies pretty much. i tell her doctors what she tells me.dr said its common her old age scared of getting sent back to hospital but they have ordered transportation for her so she doesnt get up from wheel chair when going to dr appts & i dont drive so its easier for me to go w/her & not depend on anyone giving us a ride. he volunteered (my uncle)to help her & encourage her to walk by coming over every day. something he hasnt done i told him he can but that the physical therapist was going to start coming soon bcus thats something the surgeon ordered in home physical therapy. ANYWAY he offended me said i am not responsible too young (23) and that i change my mind a lot about things &that im really a nobody to be taking care of his mother or making decisions for her. and that one of my grandmas daughters should be doing all of what i am doing instead of me. because im not reliable & he doesnt trust me. he yelled said bad words. called my aunt & mom names. i told him that i only tell the drs what she says but he wouldnt listen he said he would perfer my grandma to be at my other cousins house. & we all know that cousin doesnt want my gma at her house but he doesnt understand that. my mom told him that if he doesnt like me doing everything i do why doesnt he take care of her. he said he cant and blah blah it all lasted 2 hours of yelling,, screaming. & my gma defended him said we shouldnt upset her son he gets mad quick that we attacked him. he said he was never coming over to any of our houses anymore... it was crazy! my question is if he comes over... how should i act? what should i tell him? he has done other ****** up things to me & talked **** about me & my dad and mom before. but this! i mean come on!!! should i never speak to him again? should i be ok & not take it personal he is her son..wouldn't anyone else be kind of thankful im doing all of this? even my gmas social worker said shes surprised no one else knows anything about my grandma & that she likes dealing with me. I feel sad...angry...disappointed and offended. what would you guys do in my shoes? i feel so unwanted by him and kind of by some of my other aunts& cousins because im closest to my gma. he thinks im not responsible because he has seen me get drunk in the past and i like to go on long weekends... but i swear even on long weekends i call her drs. even the bf thinks i worry to much...HELP ME sorry it was very