Need help with Vayne

So, I have been doing a lot of ranked over the past couple of days, trying to get back into the swing of things, though a little late as it happens. I used to main Sejuani, play her almost exclusively when I got to gold in season 3 however I have been through that frustration and no more shall I subject my self to my own stubborn stupidity of playing a single champion ... especially one who can't really carry.

I have been using Vayne over the last couple of days, and though I know my mechanics leave a lot to be desired, aswell as some of my more questionable actions throughout the games ... I cannot for the life of me understand how anyone succeeds with Vayne in solo que. I understand she has a bad lanning phase, I generally just try to not die and get what farm I can. But this champion is utterly useless at times. People throw their ults wildly at your team ... suddenly ... dead. Random hook, catches you, despite using quick silver sash, I find out the hook and threshes ulti alone have killled me. I am struggling to take down other adc's and mid laners. Try as I might, when I do get the opportunity to try and kill one, they just walk away ... I use my ult, my heal ... even flash, and these bastards laugh as they walk away from me. I have been stutter walking, or orb walking, which ever term you prefer, granted I am not great, but I am not hopeless at it either, and these cheeky gits just fucking dash, dive and walk away from me leaving me with long ass cooldowns and usually some angry jungler appearing from a bush to kick my usless ass.

So, in essence, I am asking, am I going mad, just a giant god damn noob ... or does vayne really struggle in solo que?