If you have a sample size of over 20-30 games, it's not your teams it is you. You're the only common factor in all the losses, you're just bad, or at least playing badly. (there is a difference)
As for what to do about it, it's pretty simple. Stop playing janna in silver. Just don't play her ever until you get wayyyyy higher elo. If you want to know the super secret overpowered way to gain elo and be at least plat within like 2 weeks, here it is. Play support. Pick thresh. LEVEL 2 ALL IN EVERY SINGLE FUCKING GAME. People just don't respect level 2 at all.
-
Clear first wave by the time second wave gets there, not too fast so it is still in the middle of the lane, and your minions don't push under/near their tower (you want as much space between the wave and their turret as possible)
-
The second you see the second minion wave, start beating the living shit out of the 3 melee minions in the wave. Just spam auto attack those bitches. If you take/mess up a cs or two this is fine it really doesn't matter (may help to tell your adc to push second wave beforehand so he doesn't get all pissy like low elo adc's normally do when they lose 1 cs)
-
When the 3rd minion gets to around half health, walk up past it, auto attack it once, walk into the face of their adc/support (go for the support if they are playing like janna lulu nami since they have such low health) At this point your adc will last hit the minion and you'll be level 2.
-
Don't lead with hook, that's stupid. Flay them backwards and then hook them when they're slowed. If they get to around 30% HP drop ignite since this is when most people heal, and you want grievous wounds to lower the heal.
-
You get a free kill. congrats.
-
It's low elo, depending on who you kill, the adc/support will stay in lane becuase they're complete morons. Flash hook/flash flay the idiot, and get another free kill. Then push the wave in and back.
-
If you have enough for mobi boots, buy them instantly and roam either top or mid or both and get them a free kill, and you've basically won the game. congrats.
do this literally every single game, it is the easiest shit ever. To be fair my main is master like 200 lp, but it should bejust as easy for you. I did this when I was trash as well and it got me to gold in season 3 and then plat 1 in season 4.
If you have any questions, add me on moooose5 or im still toxic. They're low level accounts cuz every single one of my other accounts has been banned, but I can answer any questions you have on them, or spectate one of your games, or when i unlock thresh you can spectate me and ill just show u what to do.
Hope this helps
ALSO if you don't want to play support like this, let me know and ill add advice for a different role/playstyle as well. but this is probably the easiest given your mmr and role.