Hello and welcome to BW forums
I'm so sorry to hear how much this is effecting you. I well remember times when my LO didn't sleep well and how exhausting it was, fortunately I did not have the fear of PND looming over me. Do you have someone IRL you can talk with about your feelings and worries?
Perhaps you would like to receive some support on our PND board too? It sounds very very hard for you.
With regard to your LOs sleeping.
I can't promise a magical fix but would suggest a set nap and BT. Usually we suggest moving from A times to set naps around 1yo or when LO moves to one nap, they seem to be able to regulate their sleeping because of the consistency of the times of sleep.
Looking at the few samples you gave I would go for something like:
WU 6/7am (either way you keep to set nap and BT)
nap 12.00 - 2.30 (or there abouts, see how long he sleeps without capping and we can look at how the routine settles to see if this nap would be better capped)
BT 7.30pm
And as I said, you put him down for nap at the set nap time of 12.00 regardless of what time he woke up in the morning.
Here on BW forums we usually work out a suitable set nap time for the individual LO based on their previous routines and what suits them rather than a one-size-fits-all approach, it might be that if 12 doesn't work out to suit him it moves a little later, 12.15 or 12.30 but at each move it is set again and given time to show results (rather than moving daily to fit with WU time)
The benefit of the set nap is that it can help to bring the morning WU a little later (ie to move from sometimes 6am to more frequently 7am).
How about you try this for a week and see how he settles into it? LOs take time to adjust so it is unlikely you will see a perfect routine in one or two days but over a week he has a chance to get used to it. At that point we could look again if things are not going smoothly - for example if he is refusing or fussing at BT or waking too early or refusing to go down for nap.
What do you think?