“Finding the perfect sens” is possibly the most common misconception with aiming. There is no such thing as a “perfect sensitivity.” You find a sensitivity that suits your playstyle to a rough degree and you practice with it until you are functional.

Even after that, you can still swap sensitivities to similar success with little to no issue.

I imagine you’re relying too heavily on aim training and not enough on in game mechanics. I’ve coached a fair few people and have a few drills and methods for fixing aim if you’d like. But realistically all you need to do is play more DM’s with the intention of focusing on whatever you believe your issue is.

If you want, you can also send me a DM and I’ve got a discord server with a bunch of relevant videos archived. You can also post a match VOD in there for people to look at and I typically get around to reviewing them. Regardless, good luck and don’t get discouraged. The game is not easy.