Horrible interaction with a customer

I’m AMAB, very masc presenting due to my body shape, beard, and I’m bald as shit. It’s just easier to present that way. The best I can do is black nail polish, which I absolutely love. I was helping a pretty belligerent customer the other day and was unable to help him because he did not want to provide documentation, so he responded by calling me a fucking freak several times and tell me that “when they come for people, you will be the first to go”. Unfortunately my manager only heard my reaction to him and pushed me away, telling me to go on break and helping this Nazi piece of shit. It was only after I collected myself and this piece of shit left was I able to tell my manager what happened that he profusely apologized for the situation, but I’m still incredibly upset about the incident. I get treated like garbage by customers compared to my other coworkers based on how I look and I’ll never be able to look how I truly feel on the inside because of my body, it’s all just so fucking frustrating