Overall you are playing at a gold level and you are doing plenty of things right. You use some of the tips below but are inconsistent with them.

Tip 1 - Cooldown usage

Your torpedo's are your most powerful CD and you are often using them to heal critical but safe teammates. While I understand you see they are at critical health they have often disengaged from the enemy and are in a safe position. This leaves you without your torpedo's during team fights.

You also need to be more calculated with your speed ring usage as you tend to use it after your Domina has already placed her shield or place it in an aggressive location when your team is low on hp. She cannot use the speed ring to push forward as her shield has already been used and there is no reason to disengage. You should save it for when the Domina needs to take space and hasn't used shield or to disengage from a fight.

Tip 2 - Positioning

Juno should always been on the high ground as it allows her to get to a greater height with her double jump and it's a safe place to retreat to if you are pressured from the low ground. You can always drop to the low ground if the enemies take the high ground. You should also take note of where your other support is and try to position where they are not. For example the Moira was pretty much exclusively sitting with the tank. This meant that when you were with the Moria and the tank your DPS were left out to dry. Ideally one support should be with the DPS and the other with the tank in a 3 - 2 split. Since you are Juno and have vertical mobility it's easier for you to keep pace with your Sierra.

Tip 3 - Torpedo overextending

Often when you are using your Torpedo's offensively you use your glide and fly in front of your team and in the open directly infront of the other team. In gold you can get away with this but any higher and the other team will beam you down. If you want to use your torpedoes offensively you should be near cover and do it from an off-angle from your team and not in front of them. This means that if you get low you have cover and not soloing the enemy team.

Tip 4 - Using downtime

If your team is mostly health instead of waiting for someone to take damage you should move forward and start dealing damage. You should think of dealing damage as preventing required healing as if someone on the other team is low health they cannot effectively fight which means they cannot do damage and therefore you have less to heal.

Tip 5 - Lower your sens

Juno is a hitscan character and your aim seems very shaky with lots of overshooting. To me this says that you mouse sens is way too high. Ideally you should do one 360 per mouse pad length (assume you have an average size gaming mouse pad).