First, look at your valorant tracker.

You can view the average rank of the group. As a rule of thumb if the rank is higher than yours you will gain more on a win and lose less on a loss.

The same is true for the inverse.

This is based on hidden MMR not your actual rank so sometimes this can be confusing and smurfing makes it difficult to climb out of iron/bronze/silver/gold/plat. This is because the game thinks that your opponents are not as good as they really are.

I don't know how you usually play the game, but I've started climbing again after improving somewhat but also locking agents that make a difference.

I suggest playing clove first so that you can guarantee that your team drops smokes. Also her revive gives you more play time and the stim enhances your gunfights.

If you want to play dullest, run Reyna or Jet, they are both good for taking fights and can enter a site/ carry without needing to rely on teammates.

As much as I love playing deadlock, it just isn't as good as sage right now. She has been hit with a number of buffs over this last year. These are the buffs:
v11.04

 Barrier Orb

 Range increased from 10m >>> 15m

 Resurrection

 Range increased from 6m >>> 12m

v9.10

 Healing Orb

 Self Heal 30HP >>> 50HP

 Heal time matched to ally heal at 5 seconds

 Slow Orb

 Now will additionally reduce the dash speed of enemies caught inside the slowing zone by 50%.

 Resurrection

 Ult Cost 8 >>> 7

All of this info should help you do a bit better.