The ilvl isnt the main problem here, i just stated it as i also had trouble at 118-119-120 lvl. The power curve catch up fast.
THAT said, the main issue is that you seem to expect some easy and optimize poorly. Use a guide, take the talents suited for the spec (sin is all about crushing a single target, so poison bomb is definetly better than crimson tempest. etc) et take the azerite talent fitting the spec too. Not playing sin and have outlaw talent.
I see you’re trying outlaw too, thats fine, be sure to swap your weapons hands. the best one goes into the main-hand slot.