A healthy human being should be able to manage more than one social thing in a day, right?

I'm attending a new-to-me online grief group tonight, where I won't know anyone.

This morning I went for a walk and then popped into a shop, where we ran into friends and ended up going for coffee. I could feel my social battery depleting by the second.

We sat there for an hour before the thought 'I need to get out of here' crossed my mind.
Shortly after that, we left.

Is this normal, or 'normal for someone who's going through a lot'?