My 7 week old tries to fight sleep every time. We have to rock and pat him and sometimes that doesn't even work. He cries the entire time and it usually last about 10-15 minutes. I think he literally cries himself to sleep. He doesn't want us to hold him half the time. Is it ok if we let him cry for a couple of minutes? Or any advice on what else we can do? It's so exhausting having him scream everytime we try to put him to sleep.