Hi Selma.
to SR. Please keep posting and reading.
Regarding this:
"I've seen him have a couple of drinks and stop, but on the other hand I've witnessed him take it too far.. It's continuously back and forth, and that is why I was confused"
IMO this back and forth that is confusing you is how this man lives his life. Do not let it confuse you. So many of us who are dealing with alcoholics report that they are like two different people. But they aren't. He is not likely to stay one way or another permanently, but will likely continue to do what he has been doing. Many of us want the A in our life to stay the sober person and believe that the A will, "If only he or she would fill-in-the-blank." and many of us have lost ourselves in the process of "supporting" an A in their efforts to choose one way over the other.
What really stands out for me in your story is that this man is having seizures and still thinks he can handle his problem on his own. IMO if you have reached the point of having such serious medical issues, you need to get help. But, many alcoholics remain in denial and continue to try to go it alone. My Dad is this type and he is almost 75 years old, very sick, still drinking, and still thinks he does not need any help from anyone.
Please get a boyfriend who is not an alcoholic and investigate for yourself why you may have involved yourself "romantically" with an alcoholic. I suggest giving AlAnon a try.