You may need to bring him to the vet. It could be an abscess on/in his ear and the urinating in the house could be because he may feel a little dizzy when he moves. If it is an abscess the vet will prescribe a medicine for that and you may want to mention the urinating in the house. I could be wrong about it, so my best answer to you is to see your vet.
Clavamox is an antibiotic commonly used to treat urinary tract infections. It is always best to make sure this inappropriate urination is due to a urinary tract infection and not a different cause. Ear infections need to be treated topically; the clavamox may help but will not resolve the infection completely. Also many ear infections are yeast infections which will not respond to Clavamox. Your veterinarian will do an ear cytology to diagnose what type of infection is present and then treat appropriately.
I personally would take my dog to the vet.Better to be safe than sorry!