my 7 week old will not settle in the evening - put him to bed around 6.45 after bath and bf. He falls asleep on my boob - but as soon as I put him in the cot - he wakes and cries and boy can he cry. He spits out a dummy and nothing will settle him except my boob. He screams so much he goes completely purple and I can't bear it so I end up him with him on my boob, and we go round and round in circles until about 10pm - any advice?