I Am A 44 YO Female, In The Last Week

I am a 44 YO Female, in the last week I have not been able to eat or drink anything, if I just take a sip of water, in 5 minutes I have to run to the bathroom and it is nothing but a watery stool. Last night I started to feel better and I am of course hungry, so I ate supper, now today I feel constipated and I am very tired and I also feel Nausea's. What do you think is wrong with me?