It sounds as though you are unfortunately faced with the dilemma that comes to many owners of loved ageing pets.
Ageing hopefully comes to us all. It affects not only the outside of the body which we can see but also the internal organs. The heart liver lungs intestines kidneys bladder and brain are all affected to some degree. The unsteadiness of your ageing dog when he first gets up could be associated with these changes to his heart or his brain or a combination affect of the circulation of blood through his brain. It could also be caused by ageing or disease changes in his skeleton such as arthritis and or muscle function. In much the same way the messing in the house may just be that he does not know what he is doing or that he has no control over it due to the changes affecting bowel function and control.
The more recent problems of sickness and head tilt may be the result of disease affecting his brain inner ear and bowel. In view of this almost certain combination of ageing and sickness I have no doubt that he should be taken for veterinary examination as soon as possible if this has not already been done. We now have excellent medicines that can help the body compensate for many ageing changes especially those affecting the circulation and if there is for instance infection involved in ear or bowel then antibiotics may be indicated.
There are of course some problems which are untreatable but very often the only way of identifying these is to assess the response to treatment over a period of time and that may be what you have to do in this case. I would certainly not be recommending euthanasia in this case without a thorough examination and giving sufficient time to see how affective appropriate treatment is.
Please keep us informed of his progress. 1 call advice direct vet is always available on 0906 11 11 999 if you want more immediate advice.

14/12/05