How should I be playing Sona?

Hi, so I'm a silver 1 support main trying to get gold before preseason ends and I mostly play Sona. She's a great support because of her healing and her great teamfight ultimate. She also is really easy to lane with because most ADCs position poorly and it's rlly easy for me to get poke in with my Q and my empowered auto from my passive but I'm struggling to win games on her. For me, my games go: win lane, lose game. I think I build optimally as well. I like to rush redemption because there have been so many games where it's turned a fight around so much and thanks to it we were able to get crucial objectives. I then usually build: Ardent Censor, Locket, Zekes, Athenes and for boots it depends on the enemy team comp. I don't build full ap because it's not always reliable and I prefer the shielding from Locket, empowered heals from Athenes and Ardent and the buffs to my team mates from Ardent and Zekes. I roam quite a lot too and that has greatly improved my gameplay since I started doing that. I just don't really know what else to do. I'm not saying I'm perfect (I'm silver 1 for christ sake ofc I'm not xD) but Sona is pretty simple with her kit so mechanically there isn't much to think about so I can focus on macro. Recently, my games have just been my team mates getting caught and because one team mate is dead the rest of them feel the need to avenge them and go back into a 4v5. Also, in one of my recent games my team somehow managed to win a teamfight and there was only a Fizz left on the enemy team. Instead of coming mid to help push for tower they kept chasing and he managed to outplay THREE team mates and he got a triple kill and just ran off. Its this sort of behaviour that really triggers me and it's cost me so many games. Like I can spam ping people to stop doing things and it literally has no effect. Can anyone suggest tips to help me start winning more games? Thank you :)