Looking at your recent games, I can tell you aren't itemizing correctly. I can't tell you much about midlane/adc, but I do know a whole lot about Top lane (specifically Nasus and Renekton) and Jungle (mostly Sejuani, Vi, Gragas and Jax) and I have a small amount of knowledge on Support.
My biggest tip: Nasus, Vi and Jax are probably the easiest ways to climb in your ELO. Most Bronze players do not have the proper knowledge to stop a Nasus from stacking and him and Vi can hard carry a game... if built right.
I've looked over your builds, and you seem to be going for Dead Man's Plate a lot. When playing Nasus, you need to be passive early game and ask for a gank from your jungler if you are struggling with stacking.
Nasus' itemization is actually quite easy:
First item Frozen heart if you're vs an AD top, Spirit visage vs AP. I would grab boots after my first item, normally merc treads since Nasus gets pooped on by CC.
Second item should be Triforce... If you need the extra tankiness, build a sheen and skip into your third item and finish your triforce after. Or you can build an Iceborn, but I wouldn't personally build it.
Third item depends on how you're playing the rest of the game. If you plan on grouping get a Randuins/banshees which is what normally happens. if you want to keep splitting build an ohmwrecker (if you don't have 40% cdr by then.) This is a really good item on Nasus since it lets you tower dive easily and take a tower without it hitting you, and it gives you extra passive MS which can let you escape.
4th/5th items are very similar. Since the new items came out I now go Dead Mans Plate or Steraks, or if you need extra armor get a Thornmail, if its super late game get a Guardian angel.
Now Vi. You're building Black Cleaver... its not really a good item on her. If you are going cinderhulk, I would recommend getting a tri force since the item really goes well with her. I would try to stay away from the new items, except Dead Mans plate. Which is good on any champ since it gives health, armor, and mobility boots basically. Other than that, just go straight tank. I like building Frozen Mallet on her, to get the W procs off.
Your Shyvanna seems good, so maybe keep playing that. but if you want more clarification add me on NA: MSGhazarian. I'm on almost everyday :P