What the f*ck has happened to my baby!?

So my boy has just finished Leap 7 about 4-5 days ago (going by due date) he was supposed to be born on the 23rd Nov, but came early on the 1st of Nov.

He's never been a good sleeper, but at least went down for his naps and bedtime at night. But never slept through the night waking every 3-5 times every single night since birth. We never really experienced sleep regression until NOW. During Leap 7 there was no problem. Now he's skipping his day naps, fighting me like he's never fought before. I try EVERYTHING to make sure he's comfortable, fed, not in pain, I put him down at the right time but he just FIGHTS me for HOURS.

His current sleep schedule is like this...

Wakes up at 3:30am now (used to be 5-6am)

Skips his morning nap (which was at about 9:30-10am) he's now refusing to go down until I FORCE him around 12pm as I'm at my wit's end and he sleep until 2:30pm-3pm

Then doesn't go to sleep until 9:30-10pm at night when it used to be 6pm.

And then it starts all of over again at 4am.

HELP... He has started learning to climb things. He climbs on our coffee table and anything else he can. So that's something new. Not walking yet. Could this be because he's learning new things.