How to handle pressure from collaborators when life circumstances make it impossible to get work done?

I am looking for a bit of advice on how to handle the workload in a PhD while juggling several collaborative projects plus family pressures.

I am in the final year of my PhD which, overall, has been fairly successful to date. I am currently collaborating on a number of projects with other academics - most of which have been going on for some time and are nearing completion - which along with other work I am doing independently will form my PhD thesis. When I took on the projects I was confident that I would have the time and knowledge to turn them around fairly quickly.

However, I recently had my first child with my partner a couple of months ago and I have found it almost impossible to get much meaningful work done since (and also in later stages of the pregnancy) due to the pressure of supporting her and my child - sleepless nights, caring for the baby and her along with the additional strains on our relationship. I am now under pressure from most of these collaborators to finish my parts of the projects and this has been causing me considerable stress, which in turn has made it even more difficult to focus on projects and get them completed. I have to add that on most of these projects I have done a considerable bulk of the work, while other collaborators have at times been slow with their turn around, which is one of the reasons I now have so many ongoing projects. But I get the feeling that several of them feel I am now stringing them along but giving repeated dates for completion that I do not meet.

I feel under huge pressure and strain from multiple directions. I often do not check my emails for days knowing that there will likely be another email asking about progress, my relationship is suffering and I do not properly enjoy spending time with my child - my work seems to pollute much of my life now. Funding is not an issue as I have sources of funding that will take me well beyond the time I need to complete my thesis, but I feel I am burning bridges with other academics in the the field, which is causing me considerable stress.

I think I probably know what I need to do, but can't bear to do it... I have two first authorships and a significant authorship and am writing up a further two first authored papers. These alone would be enough for my PhD and probably a decent postdoc position. I should inform my other collaborators that I won't be able to work on their projects any longer, or at least not within the forseeable future. It would pain me to do this as I have already invested considerable time in these, and without my further input some (most?) would be unlikely to be completed and published, or would be inferior publications to what they could have been, as well as seriously damaging my reputation with these academics.

I would appreciate thoughts of people on how I should approach this - especially from people who have been in similar situations or have dealt with very slow and unreliable collaborators.