Not enough sleep ?

My baby is 4.5 months. Used to sleep 7 hours every night then naps made it 13 hours every 24 hours

Now suddenly he wakes up almost every hour crying doesn’t wanna sleep in his cot and sleeps 10 hours and is struggling to nap

Ive Tried everything to make him sleep he just won’t sleep.

Sleep regression means a change in sleeping pattern which I understand but he’s sleeping a lot less and struggling and crying a lot more now and i know only 10 hours isn’t good for his development at this stage