My dog has been licking his nose & popping his jaws. He also is very lethargic & I can't get him in from outside. He is usually very good and comes when he is called. He is 120 lbs so I can't pick him up. I can't leave him outside as I do not let him roam.

He is drinking a luot of water and not eating a whole lot. He is 8.5 years old so I attempted to express (right word?) his anal glands.

His personality has totally changed in just a couple of days.

Any suggestions?

Changes of this nature need to be addressed with your vet. Your description is a little vague and the list of possibilities is too long
He is likely not obeying because he feels like crap or hasn't the energy to get up and do what you tell him.
Don't worry so much about that right now, get him to the vet, he is obviously very sick.

Although rare conditions such as tumors could be doing this, the most common ones might be injury or a tick deep in the ear or nose.
Please don't concern yourself with obedience when your dog is in pain!

Changes of this nature need to be addressed with your vet. Your description is a little vague and the list of possibilities is too long
He is likely not obeying because he feels like crap or hasn't the energy to get up and do what you tell him.
Don't worry so much about that right now, get him to the vet, he is obviously very sick.

Agree!

Believe me I don't hurt my nany, even when he is sick. It is just that I can't get him in the house as I don't let him roam.

THank you..

Changes of this nature need to be addressed with your vet. Your description is a little vague and the list of possibilities is too long
He is likely not obeying because he feels like crap or hasn't the energy to get up and do what you tell him.
Don't worry so much about that right now, get him to the vet, he is obviously very sick.

The only reason I said he would not obey me was because he is 120 lbs and he does not want to come inside. I can't leave him outside to roam.

I don't think anyone has assumed you hurt him, I know I didn't.
But I do know that these signs are not good and he needs to be seen by a vet.
Has he been outside since you posted this?
Is he unable to move? Is that why you can't get him in?

So when are you taking him to the vet?

The only reason I said he would not obey me was because he is 120 lbs and he does not want to come inside. I can't leave him outside to roam.

I can see that you are still online and probably still looking for answers, but please respond as I am trying to give you some ideas on how to get your dog in at least.
But I need to know the situation.

Now that you have edited your question to include more information.
I'll tell you what stands out to me.
120 lbs unless you have a giant breed dog, wolfhound, mastiff, etc. is obese.
8.5 years old is geriatric, drinking lots of water.
My first guess would be diabetes, that is only a guess, you still need to get him to the vet to be checked.
There is still quite a long list of possibilities.