I know I'm a bit late but...
I have done the same thing when I was in the midst of my eating disorder. I was eating what I had been made to eat, but my head decided that the answer to my world's problems would be to overdose on laxatives and lactulos.
I didn't shit for a month because my digestive system was so fucked up. I only managed to finally poo when I was hospitalised due to a severe kidney infection.
You know in your rational brain that it was a silly idea, but the eating disorder feels triumphant because you have 'resolved' the 'problem' of gaining 4lbs. But, you are now in pain.
2 stone loss in 2 weeks sounds incredibly dangerous to me, although my disordered brain is immediately like FIND OUT HER SECRETS YOU NEED TO LOSE THAT MUCH. But it's an unhealthy cycle and will not bring you the happiness it promises. I know it's hard when before people would go insane and rage at you for losing 3lbs but when you are classed as 'recovered' and lose 5lbs, everyone is like 'you look so good' and 'well done'.
I've lost weight since last Monday, and to be honest it has triggered me to go further. That's scaring me because now, I can see that I have a lot to lose metaphorically ie jobs, driving, uni, boyfriend, family and my future.
You can and will get through this. If I were you, I would get lots of warm drinks, possibly some crackers or dry slice of toast to settle your stomach acid, and watch tv and go to sleep.
Sending 