I will expand a little bit.
The “rules” do not allow any interpretation or ‘special cases’.
The diagnosis determines the outcome.
Once you have been diagnosed that’s it, lifelong.
If you would go to the USA you would fill out a medical application that has a question:
Have you ever been diagnosed with…
That’s universal, they’re not asking “have you ever been diagnosed in the USA”.
Lying on your medical application (and getting caught) will be instant revocation of your medical certificate and pilot certification.
Your first medical application or after 10 years and a lot of financial investment, doesn’t matter it’s all gone.
Hence my earlier statement, stop lying to yourself.
There are hundreds of other career opportunities in aviation and there is the option to fly something that does not require a medical.
Now on the USA you’ll already disqualified yourself from Sport Pilot flying as you cannot have been denied a medical.