I think that Rosie is right and that you have absolutely nothing to blame yourself for. I'd go further and say I don't think you had that much choice. If over long term you are faced with anger whenever you speak seriously it does not leave you anywhere to go.
Blaming yourself is so common. My wife did that when I became ill, and it took a while and explanations from my psychiatrist to sort that out. Feeling he was not prepared to do anything and you were the only one trying for the relationship sounds quite reasonable under the circumstances, and this will most probably have left you feeling he did not value the relationship himself or our efforts.
That holiday must have seemed so full of hope. Unfortunately holidays can be artificial places where pressures are off and distractions abound. The return to everyday life and that move and his subsequent behavior must have been heartbreaking.
People do not have labels you can see saying 'depression' or 'needs medical help'. These are things they have to discover and act upon, if they are fortunate with the help of someone who cares, but nevertheless they have to be the one who does the doing.
It may be getting medical help will change him around and you may get together again as you hope, however your breaking off when faced with anger, secrecy and indifference to your feelings really had to happen.