I am going through a similiar thing with my 4 1/2 month old. He went from waking once during the night to waking every couple of hours. The only difference is my little man isn't really crying, he will settle straight back to sleep with a quick cuddle or sometimes a quick feed, but it is still sooooo tiring waking up every couple of hours. Jack sleeps in a hammock next to our bed so I can get him in and out fairly quickly before he gets worked up to a cry. Geeeeez, I hope this passes soon, i am exhausted, as I am sure you are, I really think we all just have to wait it out though.