My pomeranaina has a hurt paw!?

Last night my baby started limping really bad and my husband felt his paw and he cried and didn't want to be touched. I consoled him and he cuddled up into me as he was looking him over. This happened suddenly and since then he can't even get up. He just scoots to move on my bed. Then this morning when my husband got up to go to the loo, he stepped on him! He didn't mean to but it hurt my baby even worse! I'm very upset. Could he have something in his little paw, or could it be that my husband stepped on him earlier last evening too. I think I should take him to the vet but I don't have the money to do so. I need help!