What a lovely story!
As 'rightoguvnor' said, walking and talking about things that are embarrassing, is a good way to cover a subject like this. Maybe start the conversation by saying how much you care about him, and then go on to say something like 'I think I'm ready move things forward on the physical side, how do you feel about it? Then if he says yes, you can then say 'well in that case, I guess we should talk about contraception'. Hopefully that will get things started, and you can go from there.
If he runs away, or blusters and looks like a beetroot, you'll know that, 1) he's not ready, and 2) possibly he's not the right one for you to take such an important step with, as having sex is a natural thing to do, and if he's that against talking about it, then it's likely you're always going to struggle to have difficult conversations with him.
Don't expect things to be perfect the first few times, but if things do go wrong, try and talk about what happened, again do it while going for a walk if you still find it embarrassing.
Try and be light hearted about things if you can, maybe you could say something like, 'I'm not really sure what I'm doing, so you'll have to show me what you like', he might then say 'I'm not sure either', in which case you can then say 'OK, well we'll have to learn together then',and give him a smile, or laugh. Suggest he starts by stroking you all over, NOT going straight for the main game, and that way it's more likely to feel natural going on to the next step, but don't forget that condom!!! If by any chance he fumbles while trying to put it on, ask if you can help, with a sexy grin, and if you can do that, I think you will find that the shyness and embarrassment will be gone.
Hope this helps.