help please..

My 5 month old will not sleep 😩😩😩
He's been taking cat naps during the day. Really short like 10 min or less 30 min max and then at night still doesn't want to sleep!Β 
The usual rocking/bouncing/shhing that I do that usually works isn't working. Bath time doesn't relax him, white noise doesn't seem to make a difference anymore, he won't sit still for a book.. nothing works.. I've tried stroller, swing, wearing him, car seat, nothing.Β 
During the day he's happy one minute and crying the next.. I feel like it's because he's tired but won't sleep no matter how tires he is.. I know some ppl say it's the 4 month sleep regression but I feel like he already passed that..idk what to do anymore.. maybe it's teething? What more can I do what will help??
I'm tired, he's tired. 😭😭😭