How to Handle Rejection Sensitive Dysphoria

How do you handle rejection sensitive dysphoria. It’s causing me real issues. My main one recently has been with my boyfriend. We have been together for 3 years- and anytime he gets in a bad mood for the day- I get really anxious and worried that I did something wrong- or that I’m going to do something wrong and he’s gonna snap at me. His “snapping” at me isn’t anything bad at all. Like we were making cheesecake and I was whipping the cream cheese- and I accidentally got it everywhere. He looked annoyed so I asked him if he wanted to do it himslef and he said “yeah kinda”. And then boom- that rejection like ruined my day- I cried for two hours. How do I stop this?? I just want to be normal.