Please help – new player struggling

Hello all.

I bought this game when it first was available for purchase, but I got into it only just now. I'm a fps vet, but I'm struggling to kill any player which is not standing still for an easy headshot. It seems everyone can tank insane amounts of damage. Some of my last games:

• Died after shooting same guy 4 times with a shotgun at point blank. Are shotguns useless in this game?
• Died after putting 7 SKS rounds into a player
• Died after hitting same guy 17 times with one of the automatic weapons the scavs spawn(I think it was an AK-74)..

I'm hitting way more than the other players and keep getting owned. It also seems from twitch stream that people have almost no recoil when shooting compared to me.

Is armor and perks that OP in this game? Should I wait for a wipe so that I can kill people without feeling they are some kind of borderlands bullet sponge boss?

Please, any tips from veteran players to help me quickly get into a position where I can compete?

Thanks!