Clara, my DP was the one who wanted kids so much, not me. But when our son was born 3.5 months ago he got a huge shock.
The planned section (can you have a calmer delivery?!) was "the most terrifying moment of his life" and if anyone in the room had hurt me he said he "would have killed them all without a thought". Strong emotions voiced by a generally taciturn bloke.
When we got home he did all the right things and we got through each day ok, but my baby turned into a colicky, restless misery most of the time. He has loads of baby experience but not 24 hours a day and not when they're as grouchy as our son! He found it desperately hard. Even now at 15 weeks we still nark at each other frequently, and disagree on how some things should be done. It does feel like the essence of our relationship is still there but very deeply hidden.
I can't think of any other circumstance in which a couple have to endure such a massively lifechanging and sometimes traumatic experience and then have no time to discuss it afterwards! It shakes the foundations so deeply but you just have to be as patient as you can, allow each other space and time, and have faith in yourselves. It will get slowly easier and better, and you will see more of your old selves in one another, but right now there's no time for that because your baby needs you so much.
Incidentally, don't give up with the BF. Although supportive I think my DP secretly felt left out by it ... now he'd freely admit that not having to get up (every 45 minutes the other night ) more than makes up for us not using formula!
Hang on in there, it's a rollercoaster as they say but you will get through this. Until your mum gets back there's always MN, stay with us!