> This weekend while we were on vacation, he was pretty drunk and told me that he still loved her but couldn't be with her because of all the problems they had in the past.
Just because he loves her does not mean they are right for each other or he wants to stay with her. These are different issues, which women often think are the same issue. It helps to understand the trends in differences between men and women in order to understand the big picture, so try not to assume hostility when I talk about differences in men and women. In the mind of a man, they are different issues. The plus side is he recognizes they are not right for each other and he's doing something about it (getting a divorce).
> Is it normal that he would still "love" his ex after being married for 10+ years (and separated for 1 year)?
Yes it's normal. See above. The love between me and my 1st wife died long before I filed for divorce so this was not an issue. She was a very abusive person. Just because he feels a feeling does not mean that determines his actions. A feeling would determine someone's actions only if they were irrational.
> Then, out of the blue, he tells me on Friday night that he has tremendous feelings of shame living with me and having sex with me since we are not married.
And this is why you don't get involved with someone until their divorce has been finalized for at least a year. They need a year to sort themselves out emotionally, and maybe financially.
> and feels like we are meant to be together (a perfect match!)
You can't possibly know you two are a perfect match since you are still in the honeymoon stage. It's very dangerous to you if you don't understand what the honeymoon stage is, and you start making decisions while still in that stage. This is why I advise people to live together 1-2 years before getting engaged. Get into a routine, get a little bored, find out if you still want to be with him even during the bad times. You can't possibly know who he is until you go through some bad times together.
> But I must ask - is this what I should be doing?
Yes. He said plainly what he needs, so do that. He's distancing himself from sex because he's confused about bonding with someone else via sex. But you're in it, so keep on trying.
> Or is this really just the beginning of the end - and I should be preparing myself for that?!?!?
No, he never said it was the end. That is just your fears talking. Separate your fears of what COULD happen with the reality of what is happening now. If you don't get rid of your fear it could take over and ruin everything. Let go of your fear, don't let it influence you. You are allowed to think about the future but not to the point it makes you crazy. Live a bit more in the now.
I have a long time interest in psychology, specializing in relationship dynamics for 30 years.
(Please note, we give the best advice we can based on the information given in a post. For better advice, please include the age of all romantic partners.)