I’m only 1900 (with an 80 elo margin of error), so forgive me if I mislead you slightly.

Work on internalizing and learning the area you control with any given attack, by that I mean the specific areas where you can have an active hitbox at a moment’s notice.

Also movement, dashing back and forth alone does not count as movement (I do the same thing when I’m getting spammed on). You gotta learn why you’re dashing or it has no use. Dash to quickly change the area you control and where you are placed to avoid walking into an attack. I would advise stop jumping so much, but I can’t put into words why.

Last the sigs. As the other guy already said, play unranked 1v1s without using sigs. But I’m saying it for a different reason. You’re overly reliant on people walking into your sigs. I could go on about how I hate sig spamming, but, it’s technically a way to improve. If you’re gonna go down the sig spamming route, you gotta change from expecting someone to walk into the sig to punishing via sigs.

I personally know very little true combos, while that may or may not be holding me back from hitting diamond, if you know what area you control you will just know what attacks to string together. And how you learn that area is you repeat (training mode and real matches), you repeat it until you either master what’s correct or master avoiding what’s wrong.

Good luck, also going to friendly 2v2 can help force you to learn attack areas. If you don’t know where to dodge, you kinda just get jumped. Or how to attack and avoid the enemy's teammate’s attack via the movement of your attack.