I'm a wheel user, but I'll tell you what I can see from the video above based on 20 years playing driving games...
Your lines and approach look broadly fine, but I think you're struggling with the usual problems a pad user will have;
1. It's difficult to apply a small amount of lock, or make tiny corrections to the steering when you're using a stick
2. It's difficult to apply accurate throttle with sticks/triggers
You can see this clearly when you watch the movement of your wheel in the video and how you're applying the throttle... the movements are often jerky/hard. This unsettles the car.
Think of it like this...
The more steering lock you have applied, the less throttle you can use.
With a wheel, you can often exit corners with 95% throttle applied, where 100% would see you spinning... and doing this with the pad is incredibly difficult. In all my years playing driving games, I've only known a handful of pad users who have the dexterity to manage this at a level consistent with fast wheel users... a fraction of 1% of the fastest drivers.
The ONE thing I would say is always try and keep your steering to the absolute minimum... on several occasions (and I only watched the 1st couple of laps), I see your virtual driver crossing his hands mid corner - meaning you're using a lot of lock (maybe max)... you would never see this with a wheel user... if you need this much lock to make the corner you're over driving the car (too much speed)... take a bit of speed out of the entry/mid corner phase and focus on maximising your exit speed... this is where lap time improvements come from.
Good luck 👍
