Got into an argument with my colleague at work?

At work there s this thing we do on a tablet called the hub, where we answer questions. So this colleague -- let s call her Annie -- kept bugging me to do it even though the shop floor was busy and there were many customers. After, my supervisor, manager and Annie are all standing near eachother (already looking intimidating) and my manager says, Why haven t you don t the thing on the tablet yet? Annie says annoyingly, I ve been telling her to do it ALL day. And that just flew me off the handle. It s the fact that my manager and supervisor was there, like she was trying to throw me under the bus. So I said angrily, every time you ve told me to do it I ve literally been so busy. But I will do it now, ok. To make matters worse, my manager goes, I felt that tension. And Annie holds up her hands to my face saying, I m not even going to say anything to you. I tried to apologise but my supervisor took me to the back and said don t worry, calm down. My manager came and said I should do a dignity at work form and how I should be apologising to her. So I DID apologise and she just stared back blankly and said she just didn t like the way I spoke to her but she forgives me. But since then, there s been tension. Me and my manager aren t speaking and barely me and Annie. What really makes me mad is that my manager didn t even ask me why I spoke like that -- I m not a rude person but obviously he doesn t care (he does kinda favour her). How do I get over this please?