Two walks are too little and leaving it for 9 hours is too long. You could half the long walks and then complement them with two short, 10 minutes or so, walks, during the day. Would you be satisfied with just two visits to the toilet/day?

Don't leave the dog alone for more thn 4-5 hours a time. You need to find someone who visits the dog in the middle of the day for half an hour or so.