Claustrophobic baby?

Went at the mall with my S.O. and son to buy a few of his essentials. Kelvin is all grumpy the whole time we're out and don't want to be seated in his stroller. We have to carry him alternately inside the supermarket. He fell asleep but cries whenever we tried to put him in his stroller. It's so difficult to carry him because of his weight and without any support from his carrier or sling. I wish he could walk. Hopefully within the next few weeks he'll be able to learn how to balance and then walk.

Anyway, I'm kinda worried.. okay, okay! I'm really worried because I'm not sure if my baby is suffering from claustrophobia. Everytime we're inside the elevator he's squealing like there's no tomorrow. All the other people inside were trying to amuse him but with no luck. This is the first time it happened. The last time we're out, he's just quiet and observing his surroundings. I'm worried that in the long run he might find it difficult to breathe in enclosed spaces. I don't want him to suffer that nor the fear itself. I just hope that he's not comfy with that-kind-of-feeling inside the elevator or it's just one of his grumpy days.