You have to clearly understand that you have to play better than those you get in ranked games, so often, you have to step away from your favorite role and take a support-hero or heroes to key positions where they don't exist now.
Because it's easier to find an adequate carry than it is to find competent support, but if the game drags on, then all the responsibility will be on the shoulders of your teammates, because the first time they do the best they can, the outcome of the game depends on them.
To understand what heroes in Dota 2 are in the meta now, you just need to play a few ranked games and see the professional matches. There will be seen which hero is the best bending. But remember, while you're learning one hero's abilities and coming up with something new, he may be out of the meta by the time you learn how to play it well. That's why you should always have your hero pool that are comfortable to play with.
By picking your best heroes this way, you'll find what works for your ranking and fits your playstyle, saving you a lot of time and nerves.
Another important and positive quality to improve your Dota 2 ranking is the ability to surrender your teammates' positions and heroes: if someone is in your mid-line, give it to them and don't pick a hero, a feed, or a double mid - it's total crap, because you will never achieve anything this way. Just choose a different position and hero, for instance, a core or a hardliner. If you can't do it, take a side port and do everything you can to win, not the other way around.
Choosing the server has a lot to do with it. If a player goes to an American or European server and does not know English, it will be challenging to communicate with the team, and it will create additional pressure and an obstacle to the game itself.
The main thing here is to farm and farm, but we're not saying that you have to farm the whole game, for example, in the woods, without helping the team. You need to understand that you have to farm the creeps quickly and correctly to buy the right items as early as possible and help your team win the mid-lane or other line. Try to be happy, and keep an eye on your mental health. Don't play ten games in a row.