I crate trained my boy (now 3.5 years old). I had lots of issues when he was a puppy and I believe most of them were my fault. I came on this forum and they helped me loads
Maybe you can learn from my mistakes.
I got a big crate for him and on the first few nights he just cried constantly. He was downstairs and I was upstairs. I did keep going down to him but the crying just wouldn't stop.
So what I did was reduced the size of his crate so it was all snug and I put in the crate a blanket that has his mum/dad scent on (he still has this now - very smelly
). I also stayed downstairs with him for a while.
I also had to make his crate feel like the best area in the world and when he went in I would praise him.
I also taught my kids that the crate is his area, we do not disturb him or go in his crate.
It took a while but he soon trusted the crate and he began to sleep through the night.
I'm not 100% sure what was the 'fix' but I am fairly confident that my boy cried because he just didn't know where I was and he felt I was leaving him.
Every night when I go to bed I always let him know that I am upstairs by making some sort of noise. He seems to settle well after that.
Also as he got bigger, I increased the size of his crate.
Good luck