Yesterday I played AP Sona bot and it was just a strange game.
http://matchhistory.na.leagueoflegends.com/en/#match-details/NA1/1591120716/32574845
I made a ton of gold and racked up 550 AP, more than their AP carry. The problem was I still felt like I wasn't doing any damage because she only has two skills that deal AP damage, along with the passive auto attack once every three spell casts, so you're damage is always on cooldown. This game was also the biggest throw of all-time. The game ended with us at 10k more gold but we lost to a random ace at the 40th minute.
You really only put 10 wards, the entire game? That's the minimum I'll place when I'm non-support, wtf.
If you really want to learn Sona and supporting, learn to ward objectives before they spawn/people want to get to them (Dragon/Baron specifically). Also you don't need to stay always bot, unless you really need to babysit the ADC, you can teamup with your jungler to help you set up deepwards in enemy jungler as well as maybe invade/counterjungle. Just make sure you communicate that with your team mates. Can also do that on your own if enemy bot has backed and you see enemy jungler poke in another side of the map. Warding blue @6:30 or so (before it spawns for the second time, which should be around 7:00) might allow to cripple enemy midlaner.
Overall you need to do better at warding, because even if you can guess where enemy team might be, your team might not, and the blame will fall on you (everyone loves hating on the support). I'm not sure about Sona, but if I play an AP/pokey support, I get Spellthief's Dagger (and don't sell it), and rush it to max after Sighstone > Boots. It's a decent AP item with CDR and gold production, so that always helps as a support.
