Dealing with Strong Emotions and Irritation Towards Partner

I've been struggling with really strong emotions and getting irritated at things that I'd normally feel positively or nothing toward. I feel so bad because I'm getting irritated at my partner for him just being him and it's things that aren't actually bad. Like, he'll just ask me if I'm okay and it'll almost make me snap at him. And on top of that, when I get like this and I tell him, he'll ask me questions to try and understand and even that will push me to almost snapping. I don't know what to do. I have therapy in two days though so hopefully I'll remember to talk to my therapist about this