Won't Sleep

My LO will be 2 months on Wednesday and he won't sleep anywhere but our arms. He falls asleep in our arms and the moment we lay him down he wakes up. He knows he's no longer in our arms. We might get 45 minutes of him sleeping on his own if we're lucky. So his dad sleeps with him in his arms. I know not supposed to but he needs his sleep and we need our sleep. He wasn't like this before it just started one day. He used to sleep on his own just fine. Any tips on how to get him to start back to that? Or do you think he just needs the comfort of being in our arms?