I really don’t want to go to an upcoming work event

Why not? Think about what's in for you. Sometimes we get anxious and worry about social events, and avoidance seems like a temporary solution. Notice how I said temporarily since you will have to encounter with another work event down the road again, and avoidance won't be an option then. So, I feel like it will be a good thing to experience, in order to feel comfortable sometimes we need to be uncomfortable first.

Do you have to go? If not - don’t do it. If it gives you no good feeling than avoid going. But think about it why you don’t want to go. Do you really don’t want to? Is it going to be that terrible or is that felling maybe only in your mind? Sometimes when I don’t want to go to events (work or private doesn’t matter) but I still do it, I recognise afterwards that I actually had a lot of fun or a good time - I could just not imagine it to be not as terrible as I thought it would be 😂