Before you head for the door, your mate needs to go to the doctor to see if there is anything that might be zapping his energy. Many men are vibrant, even in their 70s, 80s or 90s so he could have some type of health issue that he needs to address.
Then you need to look at his diet. However, trying to change the diet of an older person, especially a man, is like pulling teeth and no one really wants to do that.
Many men go into their 60s, 70s, 80s and even 90s with a high sex drive but once men lose their libido and are not good conversationalist, then it might be time to move on because it will be as good as you are going to get.
Everyone would like to have a life companion, someone exciting with whom to walk into the sunset for their remaining years but if it doesn’t happen, it doesn’t mean you are not living a worthy life. Only you can decide if you are ready to move on.