Sorry to hear about your hamster, we know how you feel, we lost our lovely Syrian hamster called Trouble on17th December with a testicular tumour.
We have lost a number of animals this year and they have all been very hard to take.
My daughter (11) wrote a poem about Trouble, which is pretty hard to read, but I think may be worth a look as it has some elements from which you can get some strength.
Trouble
Kind regards