Engorged at 4 weeks PP?!

Brittany
So I left my LO overnight with my mom 3 nights ago and pumped twice during that night due to being uncomfortably full. Ever since then I have been feeling engorged constantly! Poor baby has been coughing, spitting up and gassy during feeds. How do I get this back under control?! I have not pumped in an attempt to get my supply back on track except after this mornings feed for about 3 minutes, but I am soo uncomfortable! 
Also, prior to this I had been pumping every morning in an attempt to build up a freezer stash. Should I stop this??