Social anxiety or claustrophobia?

I think I had my first panic attack two days ago, and I'm really worried about it because I just can't get the feeling of helplessness out of my head. My heart starts beating fast when I think about it.

I was hanging out with a group of friends at my friend's place. It was a small birthday gathering, and I've attended these kinds of events before, except that this time the party took place at my friend's small crowded appartment instead of a bar.

I'm an introvert, but I manage to hold conversations, and I have an active social life. For instance, I'm not afraid of public speaking, as one of the jobs I do includes lecturing, and I don't escape the social situations. However, things haven't been great in my life recently. I'm a caregiver to my sick grandma and I work a lot, which causes a lot of stress. Despite having friends, I often feel lonely, anxious and overwhelmed.

Still, what happened at the party took me by surprise. The first few hours went fine, although I felt a bit uncomfortable in a small crowded room. After a couple of hours, when everyone gathered in the room and there was no space left, I started feeling anxious, my heart was beating fast, I couldn't breathe. I shut down and I couldn't hold conversation anymore, so I was just standing there quietly, almost paralysed, while everyone else was having a great time. The things got worse when this girl made fun of me, saying something like "haha, look at her", and everyone just stared at me, making me feel even more anxious and aware of myself. I had to leave early, holding back tears.

I'm not sure what actually happened. Was it claustrophobia or social anxiety? What is the cause of the panic attack I experienced last night?