I would not do anything rash at this point. I certainly wouldn't be sending him any emails demanding that he say he love you or giving him an ultimatum. That is guaranteed to create trouble where trouble actually doesn't look to me as though it exists at this point. If you've been together less than one year, he's still a bit upset about his broken engagement and naturally feeling a bit vulnerable, what is to be gained from trying to make him say the magic words 'I love you' especially if he's made up his mind not to take any emotional risks for a little while? He will get around to it by himself one of these days if and when he feels like it. Don't worry. Or maybe he won't. Some people think saying 'I love you' is a lot of rubbish anyway. It doesn't mean they don't feel or show love though.
Yes, actions speak louder than words! A lot of men will say 'I love you' to a girl, but not treat them properly, not be nice to them, thoughtful kind honest etc as you say your boyfriend is to you. You have a man who is nice to you, thoughtful and kind but you're still not happy unless he says the 'magic words'. I think this is counterproductive. Leave him be! If you're both happy, why spoil it?
Life and relationships don't come with any guarantees at the best of times! Even people who are married break up often enough. There is no way to get a guarantee that someone will stay with you forever, even if they have said the magic words 'I do' let alone 'I Love you'. Most importantly, you love him. You care about him. You are kind to him. It seems he is returning your care and kindness, why not just leave it alone?
It is never a good idea to have 'the talk' about the relationship or how you are feeling etc. when drunk by the way.
"The only thing to do with good advice is to pass it on. It is never any use to oneself." - Oscar Wilde