I feel stupid

I’m a sub he’s the dom. We have a safeword but for the past two weeks I’m been afraid to use it. I don’t know why but the first time I didn’t use it when I wanted to he thanked me after for being able to handle what was given, sexually. And since then I’ve been to scared to use it. It’s put me into crying spells after it’s over and I feel like I can’t use my words. He thinks I’m shivering because of an orgasm but it’s just me getting scared. Please don’t judge. I don’t know where else to ask. How do I bring it up? Anyone else been through this?