SOMEONE HELP! ive been up since 3 am!

I have a 4 month old who has slept through the night since 2 1/2 months. But now is hitting the 4 month sleep regression hard. we have not had a good nights sleep around here in over a week and I'm going crazy. As I'm writing this at almost 8 am, he is still wide awake, has had 2 bottles since waking at 3 am, 2 changes, he's been rocked, swung, patted, back rubbed, left to cry it out, weve tried everything tonight and he is still wired awake. What are we doing wrong here? Please give me some advice