Winning is much more important than statistical peformance in ranking up. Your profile doesn’t list by role, but it does say that your winning percentage is well less than 50%. See How Competitive Matchmaking and Rating Works (Season 18) for details.
Edit: I went though your profile by hero, and came up with a 44% win rate for the support role (may be off a bit due to rounding). Work on your win percentage, and your rating will take care of itself.
| Hero | Wins | Win% | Games |
|---|---|---|---|
| lucio | 21 | 0.58 | 36.2068965517241 |
| moira | 15 | 0.46 | 32.6086956521739 |
| mercy | 6 | 0.26 | 23.0769230769231 |
| zenyatta | 2 | 0.57 | 3.50877192982456 |
| baptiste | 2 | 0.22 | 9.09090909090909 |
| Total | 46 | 0.440224261984582 | 104.492196301555 |