We went cold turkey to 1 nap almost 2 weeks ago with my 13month old DS. We tried the following routine: wake: 6am (ish), set nap: 11am, BT: 6.30pm ish.
Prior to this we were doing a 30min nap at 10am(ish) & attempting to do a 1.5hr nap at 1.30pm(ish), but he kept resisting the PM nap & would often not fall asleep until 2-2.30pm, meaning not enough A time to BT. His WU started to creep earlier & so we tried to make the jump to 1 nap.
The first couple of days he did 2hr+ naps, then OT struck. We stuck with it in the hopes that his bodyclock would kick in to wanting the set nap at 11am & then his naps would lengthen. Sadly, things got even more wonky - he was waking repeatedly through the nap & then at night, then his WU got earlier & his nap cut back to 30/45mins. Despite APing a C/N at tea time & doing EBT we couldn't keep the OT at bay & after 12 days we got a 4.55am WU.

I came to the conclusion he may not be ready for 1 nap as not only was he very OT, he was very miserable, crying all the time, constantly looks tired & has huge bags, so in the last few days, we reverted back to 2 naps to help him get over his OT. HOWEVER after just 2 days of catch-up, today we got nap resistance YET AGAIN.

The last few days went like this:
Wed:
Wake: 4.55am (after just 10h 15 night sleep - due to being exhausted from 1 nap days)
Nap: 9.00 - 9.45 (held him out til 9am earliest as he is a former chronic EWer. Woke him after 45mins to ensure we get PM nap)
Nap: 1.25 - 3.10 (he was actually a bit OT for this nap - woke a couple of times. Woke himself after 1h 45)
BT: 6.45pm (he was crying for bed at 6.15pm despite the nice long nap today, as still OT)
Thu:
Wake: 5.10am (10h 25 night sleep. Several WU's in early part of evening due to OT.)
Nap: 9.10 - 9.55 (Pushed nap out 10mins so as not to encourage EW. Woke him after 45mins.)
Nap: 1.20 - 3.00 (PD a little earlier than yesterday. He settled well & slept a solid nap of 1h 40)
BT: 6.45pm (slightly early to keep a lid on OT arising from long day)
Fri (today):
Wake: 6.10am (11h 25 sleep. BUT woke repeatedly every 20mins from 3.50am onwards, crying for a minute then back to sleep)
Nap: 10.10 - 10.40 (at MIL's house. Cut nap to 30mins so as to encourage earlier PM nap so he has enough A time to BT)
Nap: 2.50 - 3.50 (fought being PD for his PM nap for almost 1.5hrs with full on screaming like I've never heard. We aimed for 3hrs A after a 30min nap & he was having none of it. After 40mins in bed we got him back up & tried again a while later. Took 3 attempts before he would settle. We woke him after just 1hr to preserve BT)
BT: 7.00pm
I really don't know where to go from here

& am in desperate need of some help/guidance.
He is a 'Touchy/Spirited' combo & I believe they thrive on routine, however I am really struggling with this. He has NEVER really been in what you would call a good or consistent routine. Not for lack of trying, but his days are always so different that it is almost impossible to stick with a set A time OR a set nap time. B/c one day he will sleep 11hrs overnight & manage a nice long 1st A time & do a great nap, then the next day he wakes up an hour earlier, then can't handle the same A time b/c he is not so well rested. Same goes for set naps - works great for a couple of days then an earlier or later WU throws us for an absolute loop b/c he is either majorly OT by nap time, or seriously UT. I am just really struggling to find the right A times for him. To add to this, he rarely shows tired signs, yet he looks tired ALL THE TIME which makes me worry he is in fact chronically OT.
We have tried long AM/short PM with limited success b/c DS will just refuse his PM nap & I am unable to AP a CN in the car every day b/c of work commitments. Short AM/long PM nap has so far worked most successfully for us, however with the PM nap resistance today, we find ourselves back in the same position, wondering how to get him to take 2 naps or whether he does need to be on 1 nap after all. AAAAARRRRGGGGGHHHHH???
- Is it really feasible that he wasn't tired enough to go down 3 or even 4hrs after a 30min nap (when he has already done 4hrs A time before it)

- could he just be chronically OT & this is why he is fighting the PM nap, rather than b/c he is UT
Maybe I am putting him down for his AM nap too late & so he is already OT when I try to put him down for his PM nap 
My gut feeling is that rather than jumping straight to 1 nap (which ends in disaster every time I try

) I either need to:
a) find the 'right' A time after a 30min nap so he goes down readily (any ideas anyone

), OR
b) cut the AM nap back even further to say 15mins, to bring the PM nap even earlier & stop him from resisting it (what A time to do after a 15min nap though

)
If anyone has any suggestions/advice I'd very much appreciate your thoughts.xx
p.s.Sorry for the long post & all the questions, I'm a bit lost right now
