What should i do about this friend?!!?!?!?!? PLEASE HELP?

ast night i told a really close guy friend that i wasnt sad or anything and everything was alright, and today my sister took my phone and said a lot of rude things to him like shes dont before and told me he didnt want to talk to me ever again, he told me it was alright and he wouldnt say that but he seemed mad, but now hes mad because i told him last night i was fine, but i really wasnt and he always tells me to be honest with him and his biggest pet peeve is liars, i just didnt want him to get hurt and i dont know what to do how because he told me not to talk to him for the rest of the day. and now hes saying if i dont tell him what was going on then not to talk to him for the rest of the day.. and i dont know what to say.. i cant tell him but i cant lie to him again!