Hi op,
You are definitely not alone! My DS is 6 weeks old, my DD is 20 months and it is hard. 'It' being everything. The whole thing is just so hard, on absolutely everyone involved.
I now know that my DD was a very easy baby. Either that, or I've just forgotten the hard bits. My DS has been in and out the doctors with horrible reflux, and has now been diagnosed with a milk allergy which means I've had to give up anything with even a trace of dairy. I cried at the GPs when she suggested this, and stressed the need to read the labels on everything, purely at the thought of another thing to do. At least it does seem to have helped.
I explained to my DH today, as we walked to meet our (mostly childless) friends at an event that I had arranged, approaching 45 minutes late, that arriving for stuff on time has now been added to the list of things that are outside of my competence (I am ordinarily an excellent timekeeper). Co-ordinating the needs of newborn DS, toddler DD with our own and leaving the confines of the house - that is the extent of what I can manage. I can keep us (mostly) fed, warm, dry, and clean. And that is it. I cannot do it to any strict timescales. I also got us lost on the way there (to a destination I have visited at least three times before) - added 'finding the way' to the same list right underneath 'being on time'.
The key for me is planning. This sounds ridiculous but I've started keeping a spreadsheet where I literally map out an activity for the morning and the afternoon every single day, along with what I'm going to feed DD at meals. I find that making a spontaneous decision or coming up with an idea is impossible but if I can look at a list and follow my own instructions... As many of these as possible involve getting out of the house. Our options are limited as I don't drive and I don't have lots to spend on activities. But I've found possibilities for every day, fitted them around her nursery hours (3 sessions) and filled the gaps with things to do at home. Life is easier when I lay out clothes for everyone the night before, and pack the bags.
There are still times (often) when I am the third person crying in the room, or when I'm shouting at my DD for some misdemeanour that doesn't warrant it, or getting frustrated with my poor DS who frankly seems terrified of the world and everything in it but getting out the house and doing something, even yet another walk around the park, makes things better. I have a wrap sling, and my DS is happier in it than anywhere else, so that really helps.
I am panicking a little about winter - what is it that families with toddlers do when its pouring rain and freezing and dark by 3pm?? This realisation hit me yesterday, a rainy sunday with no plans and my despair was in full force. It got to about 10am and I looked at the clock and saw the vast expanse of the day stretching ahead... Seriously, what do people do? Where do they go? I am going to start my own thread to ask the wisdom of MN this question as I am at an absolute loss.
Other than that, it's just a general lowering of standards. DD watches more TV than I would like, the house is dirtier and messier than I would like, non-essential jobs continue to pile up in a way that I don't like and neither DC gets the focussed, non-stressed out attention that I would like to give. But at the end of the day I'm doing my best. It's a poor best, and I know that, but it's all I've got to give.
Sorry for the essay, and hijacking your thread with my own problems, I just wanted you to know that you're definitely not alone from someone who is right here in the trenches with you. I hope tomorrow is a good day.