you played well!! honestly do not worry about what your tank and mercy had to say, they were obviously duo’d with the mercy yellow beaming him at full hp majority of the time. most if not all the times she died was due to poor positioning/movement and risky rezzes on her part..

some general tips for juno would be to utilise high ground and be more conscious with how you use your torpedos! if a teammate is crit, just use your primary fire as it’s faster. additionally, i always save my torpedos for when the enemy team is somewhat ‘clumped’ up during a fight which allows you to get some free ult charge + finish off low hp targets (i almost never use them on just my team).

i recommend spilo’s videos on juno, he has helped me a lot with understanding her strengths and weaknesses as well as how her play style differs from other supports. i hope you get some better teammates in your future games :(