BDT, I could have written this post myself! My DS2 is very similar, though he also wakes after 45 minutes during the day. Unfortunately I haven't found any one thing to work, so my only advice is just go with it. I know that doesn't help at all when you're up five, six, ten times a night and completely desperate for sleep but I find my state of mind is better if I accept that this is how it is for now. I try DS2 in his cot every so often but in reality he has every nap/sleep in our bed.

In terms of practicalities, I have a cleaner at the moment, DS1 is in care three days per week and my parents are a great help. Do you have support you can call upon? I feel guilty that DS1 is in care when I could have him at home but like you I'm so tired I quickly run out of patience and have no coping skills. I know that he's super happy in care so until I'm more rested this is how it has to be.

At the very least know you're not alone, and just remember THIS TOO SHALL PASS xx