returning to the pipes - having problems

I know I should go join a pipe band, but I wanted to get restarted on the pipes on my own for now. I've not played in 20 years or so - used to play with City of Denver in the mid-80's - but have sporadically pulled out my practice chanter.

I've been trying to get back into playing again and started with just the pipe chanter, no drones. I'm having a lot of difficulty moving from the upper hand to the lower and it feels like I'm blowing my lungs out (even popping out the corks in the drones!). Am I doing something wrong? Am I just that much out of shape? Or could there be a problem with the pipes (P1 poly pipes from Dunbar)?

I appreciate any response. Thanks!