I am happy to read that you have a new Dr. who is going to help treat your symptoms and explained what is going on w/your health. Once the meds kick in, you should begin to feel much better and hopefully the meds will help with your emotions being on a rollercoaster.
As for holding out hope. We all do that each and every day, and it took me quite a while to actually let my xh go after his second escape. It's normal because as a lbs, we think that all is well when they make a false reconcillation and say and do the things that they think we want them to say and do. It's far more difficult to let go the second time around. You are human, you are normal and what you are experiencing is very normal.
I am sorry he didn't acknowledge your birthday, but I'm not surprised. He's truly in the tunnel and it's still all about him. Try to keep your expectations to zero and I know that this is difficult, but you have to do it or you'll continue to be disappointed and hurt by his lack of contact and empathy.
Lou, take those road trips, enjoy your life, live it to the fullest and know that no matter what happens, you are going to be just fine with or without your h in the picture.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.