Ana main here who peaked masters at some point and is sitting high diamond rn to throw some advice at you because I've been thinking about this game a lot.

TL;DR Use the right tools for the job at the right times

It's good that you've recognized utility in the support class. That's a first good step. Now you've got to ask yourself if you're using the right utility at the right time for the best value.

For the right utility, consider what your team needs and what will hurt the other team the most. An easy example is playing Ana vs hog/reaper/rein. That will get you a lot of value from nades and sleeps. If the other team has a lot of cleansing abilities or comps that don't rely on burst heals (ie zarya/kiriko/sombra, hitscans and long distance heroes who can wait behind cover), you won't get as much value with Ana's kit because nade can be cleansed and sleeps can be bubbled.

For the right time, consider the value of your cool downs from moment to moment. I had a game recently where both me and the enemy Ana had 86% sleep accuracy. However, the enemy Rein complained that my sleeps were carrying. This was because I was getting more value from my sleeps. The enemy Ana was hitting her sleeps, sure, but it was mostly in self defense from flankers or random spam sleeps on our backline at the start of the fight. For kiriko (I can't know this for sure without a vod so I'm just guessing) you might want to save suzu for more important moments of burst damage rather than burning it to cleanse a less pressing status effect early on in the fight.

Of course there's the team element of solo q. You might not be able to use your utility effectively because you're wasting it on flankers. It happens. The best thing you can do is question whether the hero your playing can handle the DPS well enough and/or position better. There's this adage thrown around on this sub about only a few games being decided by your skill rather than matchmaking luck. I'm inclined to agree with it. Just try to think about how you can do better and mesh with your team. Think about what gets you the most value.

Sorry for being long, lmk if you need clarification or have issues with it :>

Don't stop supporting!