I am sorry that you are going through such a difficult and life-confronting time at the moment

FWIW, i don't see this as the final end to the relationship. From my experience, having a child changes the couple dynamic. suddenly from the moment our babies are born we are thrown head first into a new system of life, love, hardship and reassesment of who we are and who we are becoming. and importantly, it takes time. If the foundations of the relationship are strong (mutual respect, shared dreams etc) then this current hiatus could just be one of those moments of fear and reflection for what was, what is, and what will be. My DH and I went through this about 18 months ago and man, it was devastatingly hard and scary. we both questioned what the purpose or future of our love and shared life story and both of us wondered if it was worth going through this massive change together. but when we thought really long and hard (and with the help of a counsellor and long meaningful and respectful chats with eachother) we realised that the things that brought us together in the first place and bouyed us into having a child in the first place were still really important to us and still there...just a little bit hidden under the weight of change that any new child can bring.
at first our actions seemed arbitrary in that we would 'organise' couple time together (ie finish work early and see a movie before picking DD up) or heading out together before work for a coffee etc. but it seemed to helped, and gave us the much needed break to calmly and tenderley bring ourselves back together as a couple.

from what you have posted, although it must of been devasting, i have been there (on both sides!), but there can be hope. it might take superhuman strength, but if you are both willing to give it even half a go it could work, and if it doesnt at least you can both hold your head up high and know that you guys tried your very best.

HTH