Welcome to SI. I'm sorry you're here, but I think you'll find lots of great people here. Infidelity happens to some of the best of us. Having met some remorseful WSes, I'd even say some of the best of us betray their partners. Good people sometime do bad things.
How much lurking have you done? In particular, have you found the Healing Library and the 'bull's-eyed' posts in JFO? If not, check 'em out - lots of good info.
Also, on the WS forum, there's a thread called something like 'What Every WS Needs to Know' - check that out for sure. If it makes sense to you, print it out for your SO to read.
I feel like he thinks there should be a time limit for my hurt. He has done everything right and at this point, that should standout more than what he did wrong.
First, a year is not enough time for the vast majority of us to heal. It's just too big a hurt. Figure 2-5 years to recover, with life getting better as time goes by and you do the necessary work.
I suspect a WS who wants his/her BS to heal fast really wants to find shortcuts through the WS healing process. That's a terrible approach because it's not going to work.
The WS needs to take full ownership of what s/he did, AND the WS needs to change from cheater to good partner. That's a lot of painful, difficult work. IMO, the WS can't do that work without IC (individual counseling).
My W has been an ideal remorseful WS for over 3 years, and our MC still thinks it's too early to trust her.
I was terribly sad into my 3rd year. Feeling awful sadness in your 13th month sounds healthy to me.
Uncertainty seems reasonable for a long time. You still have a lot of feelings to work through; so does your SO, and he has to make changes. At this point, who knows if he'll succeed? And if he does succeed, you might decide to dump him anyway. As I say, uncertainty seems reasonable. (Again, I remained uncertain about the success of my R probably for 2+years.)
In any case, read here. Post your questions and concerns. Take what makes sense to you and leave the rest.