I have an idea
https://www.youtube.com/watch?v=aYexL1JDUpc
There ya go, if challenger ryze can beat a challenger diana
Then you can beat whatever diana rank same as yours.
You are complaining ryze is really weak, just like LL Stylish complain how weak is zed but hey at least he makes it work. So your choice, either you make ryze work by learning match up and improve or just give up.
Stop saying, ryze 2-3 item vs X ap champ 2-3 item ryze auto weaker.
I give u a clip go watch, next time just search youjtube, there will always something you can do, its just u dont/cant do doesnt mean there is nothing u can do. Even my suggestion is not bad, if you cant kill her, simply bait/wait her Q then just spam ur abilities and push wave then walk back to ur turret, just farm and wait for opportunity, I can tell your rank is not high by all your logic and its ok, dont tilt and improve man. if you find it too hard then just move on to other champ, I suggest u play malz ezpz, press W push wave back, press R win fight :D.
Remember if you cant figure out a match up, go youtube :D and watch, if a challenger can beat a challenger using that method, you can do the same because ur enemy is not challenger either, so u dont need to execute it flawlessly like the challenger but it should be good enough to win you the lane :D, but after that rotating etc its up to u :D !