I have been dating someone who is 2 years sober. He had a really sucky phase last winter, and as bad as things got, he did not drink. He is proud of himself for that.
It is, as they say, where the rubber meets the road.
If recovery never got tested, if one stayed sober only when things were relatively easy, then that's not recovery is it?
This is what I read in your concern: "I have a lot to do with his sobriety. If I act a certain (perhaps) or if I cushion the blows of life, he will do better." It is classic, we've all felt this way. But it is an illusion.
I know, since the original post, you have had a "talk" with him. But still you're having those guilt pangs. I just want to try and help you to let go of them. Life happens. To every one of us, sober or not. It's how we respond to Life that matters.
Maybe take a breather -- go no contact for one week. Evaluate how you feel at the end of that time. Then give us a report!
I wish you the best with this - it's tough