Okay, I watched your vid and I have a few bits of advice.
1. You shouldn't build attack speed so early on Graves. In fact I wouldn't suggest Ruunan's at all. Graves's quickdraw gives an attackspeed boost, so you should build mostly attack damage to take advantage of this.
2. Practice last-hitting more, you'd be surprised how much more gold you have if you last hit well. Or maybe you wouldn't be surprised, idk.
3. When you saw fed Vladimir teleporting in you and Varus should have initiated instead of hanging way back. As it was they could have killed Vladimir if their teamplay was better.
4. Train yourself to dodge skillshots like Nidalee's spear. It moves very slowly so there isn't too much reason not to dodge it unless dodging it would get you killed somehow. Remember you can use quickdraw to dodge skillshots too.
5. I would suggest learning to smartcast your skills. If you don't want to, at least put ignite on smartcast; you'll take much less time to ignite people.
Gl and hope you get back into the feel of things quick. And you play on the EU servers, btw?