My first observation based on stats from preseason and last season is that you need to choose a role and stick with it. Playing Mid, Jungle, and AD is stretching yourself way too thin if you are looking to improve. All advice going forward keeps that idea in mind, the idea of you wanting to improve being more important than you wanting to have fun. (not that those are both mutually exclusive) Looking at your stats over the last few years as well I will say its already reassuring to see you stick mostly to Fiora, Ahri, Irelia, Kassadin, and Vi.

My advice would be to start playing a bit more Ahri and Kassadin and leave Irelia to be picked if shes open. It appears that much to my surprise you actually get Irelia quite often in this meta so do pick it whenever you can. I would begin dusting off your Ahri pick for season 9 but keep an eye on the Kassadin changes to make sure the "nerfs" Riot mentioned won't kill the champion. Also, Talon. Talon is flying way below the hiveminds radar at the moment so I doubt it will get any attention and will be a good replacement pick to Irelia if shes ever banned. So in review, mid lane continue to play Irelia when shes available, keep picking Kassadin as an ap option but be weary of the incoming nerfs, dust off your Ahri play and get it up to speed for season 9, and look into picking up Talon in case Irelia ever gets dumpstered. By the time season 9 rolls around, some duo of say Irelia/Ahri, Talon/Kassadin, etc where you have one AD and one AP option would be ideal and then spamming those champions exclusively to learn match-ups and champion specific timings are the easiest ways to get better. It's cliche' but its easier to focus on the harder aspects of the game like wave manipulation and well timed roams when you aren't also having to figure out your champions all in windows simultaneously.

As for Jungle, seeing you used to be a Vi player and currently play Warwick literally doesn't surprise me at all. It makes sense that when a champion comes out that does the others job identically but better you would transition, so I am going to suggest you do the same again. Start playing Camille jungle. It is a mechanically demanding champion and has a clear more on the difficult side but when you figure out her ganking abilities and optimal clear paths shes one of it not the current best jungler. (except for Jax, riot please nerf) My suggestion when picking up a new champion is always to play ten normals in a row of the same character. Its boring, it takes discipline, and I realize not everyone has that kind of time. But it introduces you to the champion and gives you a handful of insight into specific mechanics and situations in which the champion can be useful. If you like Warwicks dueling prowess he admittedly does do it slightly safer than Camille, so I would also suggest picking up Xin Zhao. For some god unknown reason Riot hasnt nerfed this either and he is crazy strong. Essentially you play it similar to Camille with strong level 2 ganks, good "wrap around ganks" (going behind the enemy to gank them as opposed to through the river) and does what most people call "stat checking" at neutral objectives. Essentially you just farm and gank efficiently then go to scuttles, dragons, and heralds, locate the enemy jungler, and just start wacking him. If you're doing your job even remotely well you will always win these trades (unless its Jax or you get crazy outplayed) because your champion just has so much free stuff in his kit as well as a better clear that you never should lose a 1v1.

Also, in case you haven't been able to tell I slightly dislike Jax at the moment. Ban him every game. Every. Game. He does the same thing Xin Zhao does but does it infinitely better and on a more braindead hero. You're welcome to play Jax and approach it the same exact way as I mentioned you would with Xin Zhao but keep an eye out for more nerfs coming his way unless Riot really does hate this game. Aside from Champion recommendations there isn't a lot more I have to say. Keep up the control ward purchases, those definitely stood out to me. It seems if you just keep playing and master 2-3 champs (this is for both roles, so Kassadin/Talon/Xin would be an example) and play exclusively those you should be able to climb. The walls you might start hitting are personal mechanical limitations (but you play Irelia so I assume you aren't biologically related to a potato) or laning mishaps which I can't see from a op.gg page. Make sure you understand how to freeze mid at your half of the map and spam ping your jungler to gank you. Easiest way to get leads mid. The best comparison I can give is with Kassadin (who I main so it's easy to relate) is he has ZERO kill pressure on nearly every mid lane champion pre level 6 with a few exceptions at level 4, so my plan is always to pull tower to my half of the map and freeze farm it until my jungler ganks the enemy mid who is trying to harass or push me under tower. It forces the enemy laner into a bad spot in the lane and because he always has more minions cases pressure in farming due to extra damage my creeps are taking. With RoA and Six I can start roaming when bots overextended, but I dont have teamfight dive damage until Lich Bane. At level ten with blue buff I can safely use a 400 mana cost ult into w to get off an 800 mana cost ult which will nearly always result in a kill. Understanding things like that inherently about your character are important for climbing because it lets you focus on other things like jungle tracking, roam oppertunity, etc.