How do I stop this 14 week old puppy from crying in the crate?

Hello, we got this maltese puppy from a reputable breeder 2 weeks ago. he is currently almost 15 weeks old. the first night he cried for hours, and we expected that. we would check on him least twice to take him to go potty, and he did do that. we placed him back in the crate and consistently cried throughout night. we tried several things in these two weeks, all to have failed. we placed a blanket on all but the front of the cage; a shirt with the scent of my sister (since he loves her the most); placed a chew bone he likes in there, etc. we even left the tv on at night. i have tried placing treats in there and he would go in halfway and come out. the thing we worry about is when he cries, he CRIES for hours and hours. from what people have told us is that puppies usually cry for hour or two. but this dog cries and howls for four to five hours (with bathroom breaks). we worry that he can really hurt himself. also we might think, can there be something wrong with him? isnt he eventually supposed to get tired and just give it up after a certain time??? please help!!! thanks