Leap 4 frustration to the max! Send help

Ladies my son is going to be 16w on Tuesday.

Let me tell you things were going smoothly, and then BAM.

Crying non stop even screeching, fighting sleep, kicking, squirming around, bending his whole body back.

He will cry even if I move him, or rock him in a bouncer.

Not only that, he was good about sleeping in his pack n play next to me, however now only sleeps at night for 2 hours in there and will cry unless I plop him next to me and seconds he is out like a light. (I bed share once in a while because I'm one tired mama, and yes I know how to bed share safely).

I change his diaper before feeds and he cries to the point where he pees all over the place and sometimes explosive poop, and I have to change his clothes, disinfect everything or even giving him a bath because whipes just won't do it.

Now he can't stop stuffing his hands into his mouth, and will suck on anything(mostly). Sometimes after he drinks his milk and he is done he wants to suck one something and he makes himself gag and spit up.

I'm frustrated to the point I cry almost everytime he screeches, and I try everything and nothing works..until it does. By that time I barely get enough sleep for the next day for work or chores I have to do.

Wish I seriously had like 10 arms..I have to leave him sometimes crying to use the bathroom or shower or make something to eat, I feel horrible but what can a single mom do?