Anal Pain

My boyfriend and I worked to prep me for anal for 3 months. We used toys and he fingered me and it was AMAZING... But when we actually did the real thing with a TON of lube it hurt. But the aftermath has been way worse than the actual act. My asshole is EXTREMELY sore and I can't poop. It's been a whole week and I have barely pooped and when I did it hurt sooooooo bad. What do I do??