I'm very sorry that you and your DH are going through this. It so very hard. I thought I might tell you our story:
We tried to conceive for over 6 years. Through a battery of tests and two rounds of ICSI.
We were incredibly fortunate to conceive our twins on the second round of ICSI.
Our fertily problems stem from a medical condition my DH has. I'm fine.
I truly never blamed him and although I was desperate to be a mother I would never have left him in a million years.
We both made a conscious effort early in our fertility journey to try to 'protect' our relationship. To look after each other.
We deliberately made plans that weren't baby focused so we travelled and built a house.
We deliberately considered our 'plan B' for our lives if we couldn't have our own children. We started looking at adoption and also thought about how we might build a child free life (Google 'more to life' there's an excellent web site)
Infertility doesn't have to kill a relationship, but you have to put as much effort into developing your relationship as you do to making a baby.
Being a parent is wonderful but really really hard - you need each other to love and support each other through the cracks that sheer exhaustion, worry and guilt can put there.
Re IVF - I don't judge at all, but I don't pretend to understand your choice. I would have gone through pretty much anything to conceive.
I will say this though - IVF is very hard but in my personal experience it's not as hard as being pregnant (I had a difficult pregnancy) or as having newborns.
I took a very workman like attitude to our IVF. It was just a series of small steps to be got through. I just grit my teeth and got on with it. I didn't have storms of weeping or hysterical outbursts. In fact as we told no one (not family, friends or employers) no one even noticed any difference in me.
This is not to say that it's necessarily the right thing for you but just to offer a different view. IVF was very hard - but it's not nearly the hardest thing I've done.
I suppose what I'm trying to say is that we fought for our relationship every bit as hard as we fought to be parents.
And once we were parents we had to fight for it all over again.
Talk to your DH. See if you can find a way through. Maybe there won't be, but you'll know you gave it every chance.
I wish you both the very best of luck. 