What am I doing wrong?

It's very easy for me to find an excuse for why I lost. When im 0/0/4 mid with 60 more cs than the enemy mid and my top is 0/7 it's easy for me to say that my top lost me the game.

However, I'm finding that every lane but mine loses every single game I play or one particular lane loses so hard that they have completely ruined the game for everyone.

Obviously, I'm the common denominator in my games so it must be my fault somehow. Maybe I just random bad teammates? Nope. That would have to be some shitty luck for it to consistently happen over the past 50 some games. It just must be my fault.

Last game for example I was Morgana support. Despite blackshielding basically on cooldown my adc was continually out of positon and went 0/4 in lane. After that I decided I should roam. The adc then decided she should roam and proceeded to feed kills to other lanes like crazy even though we had won those lanes. She effectively lost us bot and then lost us every other lane. Somehow, that's my fault.

I had another game. Went 0/0/4 mid. Gave all the kills to our Eve and then roamed with her to stomp other lanes and the enemy jungle. She had all of the kills on our team pretty much. Late game she suicided into the enemy jungle (around 20 some minutes in) for w/e reason and did this repeatedly. I accept that this is completely my fault.

Can anyone look at my op.gg and tell me why I'm such a terrible player that keeps losing his team the game? http://na.op.gg/summoner/userName=morgana+ultima