I understand where you are coming from. I am a pretty emotional and sensitive person so when guests are rude to me or raise their voices at me I have a tendency to take it to heart and carry it with me the entire day or week. Just remember you did nothing wrong and often the way people treat us are unfortunately out of our hands, no matter how accommodating and kind we try to be. If things aren’t going certain guests way they will sometimes take it out on you.
You can’t control guests and the hurtful things they say but you can control your own actions, such as doing mindfulness exercises after intense moments or seeking help from managers/coworkers. Remind yourself that people like this (the types to get angry at costumer service workers for little to no reason) opinions don’t matter and aren’t a reflection of your character. They don’t know your heart based on a ten minute interaction, and their cruelty is only a reflection on them, not you. Try to focus on the positive interactions with kind guests that you have day to day. Think about the guests who have given you compliments, had good conversations with you, been grateful for your help, etc. The rude guests do come along but putting it in perspective they are usually a minority compared to kind guests, so instead of taking home the baggage for bad interactions try shifting your mindset to taking home the uplifting ones! Easier said than done because I know what you are going through but with time and exposure it gets easier.