No drain after removing clog from bathroom sink

Hi there! So my bathroom sink was draining very very slow. So I YouTubed how to fix the situation and it seemed easy enough. So I followed the steps in the video about taking apart the assembly beneath the sink and sure enough there was a clog and I removed it and put everything back together just as I took it apart. However now as I put water through the pipes it will drain fine for a few seconds and then back up. I have confirmed that everything down to the P trap flows smoothly. However, when I reconnect the P trapto the pipe coming from the wall is when I’m having issues. We recently had a snow storm so I figured maybe it was the vent on the room clogged not allowing pressure to release but all of the snow is not melted. Another way I can say it’s not the pressure vent is the toilet drains just fine. So I doubt the snow storm effected it. Any idea on how to fix this issue? I have made sure the P trap is angled in a way to have the best gravitational flow yet I am still at a loss.

Clog in the drain line after the trap. Very few drain clogs are entirely in the trap, actually almost never. Snake your drain line and replace the accordion clog/leak causing piece of your drain line with a solid tube.

You have a clog it, needs to be snaked

Thanks! The only thing that’s weird about that is that it was draining okay before, it was just slow. Now it’s compleltly backed up worse than it was before.

at the big box stores or any hardware store the sell a simple
hand crank drum snake very easy to use jus don't force it down
there is a "Ty" behind the wall and you have to get it past that
it will get easier once its past that point patience is key